What’s the answer to this science problem?

Answer:

Group 14  

Explanation:

The elements of the Periodic Table are arranged into 18 Groups.

Among the "main group elements" — those in Groups 1, 2 and 13 to 18 — the number of valence electrons —  the number of electrons in the outermost energy level —  corresponds to the last digit of  the Group number.

Thus, Group 14 contains the elements with four valence electrons — C, Si, Ge, Sn, Pb, and Fl.

An isotope having the same number of neutrons as Sulfur-32 would have a mass number of 32 and atomic number of 16. This is because S-32 has an atomic number of 16 (16 Protons) and mass number of 32 resulting in 16 Neutrons (32-16).

To find the isotope that has the same number of neutrons as sulfur-32, you must look at the atomic number and mass number. An isotope is an atom with the same number of protons but different numbers of neutrons. Sulfur-32 has an atomic number of 16, so it has 16 protons. Its mass number, 32, is the total of the protons and neutrons. This means, it has 16 neutrons (32-16 = 16). So, any isotope with a mass number of 32 and atomic number of 16 has the exact same number of neutrons as sulfur-32.

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Answer:

Of course :may include all of these characteristics

Because all answers are correct :they react with acids that have H+ ions and they all have OH- ions so they can be electrons donors and produce these ions in solution

:)

Answer:

The answer is may include all of these characteristics.

Explanation:

In chemistry, the term bases is used to describe substances that release hydroxide ions in aqueous solution. They are also generally proton acceptors as well as electron pair donors. Some examples of them are the hydroxides of the alkali metals and the alkaline earth metals. Due to this, the correct answer is letter D.

Answer:

H =2; I = 2; J = 2  

Explanation:

Carbon is element 6 in the Periodic Table.  

Start at element 1 (H) and count from left to right until you reach element 6 (C).

You get the electron configuration

C: 1s² 2s²2p².

Thus,

H =2; I = 2; J = 2

Answer:

H=2

I=2

J=2

Explanation:

i took this warm up

Answer: When you burned the skewer tip coated with copper sulfate the green light is emitted

Explanation:

when the copper is burned it makes a green light

Answer:

"Freezing point  and ability to react with oxygen" are chemical properties

Explanation:

The change of liquid into solid is the freezing point. The melting point is more than the freezing point in certain cases of mixtures for certain organic compounds like fats. As soon as the mixture freezes it becomes solid and which results in change in the composition from the liquid and solid in this way the it drastically reduces the freezing point. The melting point gets higher due to the pressure. This happens due to the release of heat of which results in the rise of temperature to the freezing point .Also the reaction of elements with oxygen which leads to formation of new substance is also an chemical property

Answer:

n≈8,29×10⁸ moles

Explanation:

Nᴀ=6.02×10²³ (constant)

n=N/Nᴀ=

[tex] = \frac{ {4.99 \times 10}^{32} }{6.02 \times 10 ^{23} } = 828903654 [/tex]

≈8,29×10⁸ moles

Answer:

U --> Th + He

Explanation:

Alpha radiations are emitted as a result of radioactive decay. The atom emit the alpha particles consist of two proton and two neutrons. Which is also called helium nuclei. When atom undergoes the alpha emission the original atom convert into the atom having mass number less than 4  and atomic number less than 2 as compared to parent atom the starting atom.

Alpha radiations can travel in a short distance.

These radiations can not penetrate into the skin or clothes.

These radiations can be harmful for the human if these are inhaled.

These radiations can be stopped by a piece of paper.

₉₂U²³⁸   →   ₉₀Th²³⁴  + ₂He⁴  

Answer:

m(CuSO4×5H2O)=424.0 g

M(CuSO4×5H2O)=249.68 g/mol

n=m/M

n(CuSO4×5H2O)=1.7 mol

There are 9 atoms of oxygen in each formula unit of CuSO4×5H2O. Therefore,

n(O)=8.5 mol

M(O)=16 g/mol

m=M×n

m(O)=135.6 g

Explanation:

Answer & explanation:

Soil carbon transformations have two phases: The first one is the atmospheric carbon dioxide (CO₂) fixation phase, which is performed by photosynthetic organisms, in which there is synthesis of organic compounds.

These compounds return to the soil and are used by organisms that regenerate CO₂ during respiratory oxidation reactions, using energy for their maintenance and growth.

After this, the regeneration phase begins, which corresponds to the stages of decomposition of organic molecules by the action of the soil microbiota.

Thus, soil microbiota (mainly fungi and bacteria) use waste components as a substrate for energy and also as a carbon resource in the synthesis of new cells. Energy is supplied to microbial cells by the oxidation of organic compounds. The end product is CO₂, which is released into the atmosphere.

Answer:

only columns

Explanation:

All atoms of elements present in same group or column having same number of valance electrons. Thus the elements in same group having same properties.

For example:

Consider the second group. It consist of alkaline earth metals. There are six elements in second group. Beryllium, magnesium, calcium, strontium, barium and radium.

All have two valance electrons.

Electronic configuration of Beryllium:

Be = [He] 2s²

Electronic configuration of magnesium.

Mg = [Ne] 3s²

Electronic configuration of calcium.

Ca = [Ar] 4s²

Electronic configuration of strontium.

Sr = [Kr] 5s²

Electronic configuration of barium.

Ba = [Xe] 6s²

Electronic configuration of radium.

Ra = [ Rn] 7s²

They are present in group two and have same number of valance electrons (two valance electrons) and show similar reactivity.

They react with oxygen and form oxide.

2Ba   +   O₂   →    2BaO

2Mg  +   O₂   →    2MgO

2Ca +   O₂   →    2CaO

this oxide form hydroxide when react with water,

BaO  + H₂O   →  Ba(OH)₂

MgO  + H₂O   →  Mg(OH)₂

CaO  + H₂O   →  Ca(OH)₂

With sulfur,

Mg + S   →  MgS

Ca + S   →  CaS

Ba + S   →  BaS

Answer:

7. The higher the temperature is something the greater it's Thermal energy

8. The Change in state from gas to liquid is called Condensation

9. Energy that comes from bonds within matter us called Chemical reaction

10. The change in state from liquid to has is called Vaporization

11. Gas bubbles forming through out the liquid is called Boiling

12. Liquid changing to gas only at the surface is called Evaporation

13. The change in state from a solid to a liquid is called Melting

14. The change in state from a liquid to solid is called Freezing

15. The Law of conservation of energy states that during any change, the amount of energy stays the same.

16. Another term for a chemical change is a Chemical energy

17. In Sublimation particles pass directly from solid to gas.

Explanation:

Answer:

7) Thermal energy, 8) Condensation, 9) Chemical energy, 10) Vaporization, 11) boiling, 12) evaporation, 13) melting, 14) freezing, 15) Law of Conservation of Energy, 16) chemical reaction, 17) sublimation.

Explanation:

7) The higher the temperature of something, the greater its thermal energy.

8) The change in state from gas to liquid is called condensation.

9) Energy that comes from bonds within matter is called chemical energy.

10) The change in state from liquid to gas is called vaporization.

11) Gas bubbles forming throughout the liquid is called boiling.

12) Liquid changing to gas only at the surface is called evaporation.

13) The change in state from solid to liquid is called melting.

14) The change in state from liquid to solid is called freezing.

15) The Law of Conservation of Energy states that during any change, the amount of energy stays the same.

16) Another term for a chamical change is a chemical reaction.

17) In sublimation, particles pass directly from solid to gas.

The density of lead if cube measuring 2 cm per side has a mass of 90.8 g is 11.35 g/cm^3

Explanation:

Density is equal to mass is divided by volume.

It is given that mass of 90.8 grams

we can find the volume of cube by height multiplied by width multiplied by depth.

Because all sides of cube are of same length.

Volume just ends up being 2^3

(2 cm)^3 = 8 cm ^3

Now plug both of these numbers into density equation

ρ =m/v

=90.8 g / 8 cm ^3

=11.35 g/cm^3

Answer:

It is true that earth was once covered with oceans and little dry land.

Explanation:

Over the course of around four billion years, the Earth's oceans have lost about a quarter of their original mass. Today the atmosphere is rich in oxygen, which reacts with both hydrogen and deuterium to recreate water, which falls back to the Earth's surface. So the vast bulk of the water on Earth is held in a closed system that prevents the planet from gradually drying out. According to the researchers,  the continents emerged relatively suddenly from an ocean that covered 95 percent of the Earth's surface. The appearance of large masses of dry land would have caused more extreme weather, changes in ocean currents and the emergence of proper seasons. In turn, these environmental changes may have led to rise in atmospheric oxygen that enabled the explosion of new life forms around 500 million years ago.

Answer:

Explanation:

`1. Moss and ferns

2.  Mammals

3. True

Answer:

 Mass of PbS = 9.26 g

Explanation:

Data Given :

mass of H₂S = 5.00 g

mass of PbS = ?

Reaction Given:

                Pb(CH₃COO)₂ + H₂S ----→ PbS + CH₃COOH

Solution:

Balance the equation:

                      Pb(CH₃COO)₂ + H₂S ----→ PbS + 2CH₃COOH

Now Look for the number of moles of H₂S and PbS meta

                    Pb(CH₃COO)₂ +  H₂S  ----→  PbS  +  2CH₃COOH

                                                1 mol          1 mol

So,

1 mole of H₂S combine with excess (unlimited) supply of Pb(CH₃COO)₂ and produce 1 moles of PbS

Now Convert moles to mass for which we have to molar masses of  H₂S and PbS

Molar mass of H₂S = 2 + 32 = 43 g/mol

Molar mass of PbS  = 31 + 32 = 63 g/mol

                    Pb(CH₃COO)₂ +       H₂S       -------→            PbS      +  2CH₃COOH

                                                1 mol (34 g/mol)          1 mol (63 g/mol)

                                                     34 g                              63 g

So,

34 g of H₂S  produces 63 grams of PbS.

Now

What mass of silver is produced from 5 g of H₂S  

Apply unity formula

                          34 g of H₂S   ≅ 63 g of PbS

                          5 g of H₂S   ≅ X g of PbS

By doing cross multiplication

                     Mass of PbS = 63 g x 5 g / 34 g

                     Mass of PbS = 9.26 g

To balance the given equation, add a coefficient of 2 in front of CH3COOH. 0.147 mol of PbS is produced, which is equal to 35.19 g of PbS.

To balance the given equation, we need to ensure that the number of atoms of each element is the same on both sides of the equation. Let's start by counting the number of atoms for each element in the given equation:

From the above counts, we can see that the number of oxygen atoms is not balanced. We can balance the equation by adding a coefficient of 2 in front of CH3COOH:

Pb(CH3COO)2 + H2S → PbS + 2CH3COOH

Now, the equation is balanced, and we can calculate the number of grams of PbS produced. From the balanced equation, we can see that 1 mole of PbS is produced for every 1 mole of H2S reacted. The molar mass of H2S is 34.08 g/mol, so 5.00 g of H2S is equivalent to 5.00/34.08 = 0.147 mol. Therefore, 0.147 mol of PbS is produced, which is equal to 0.147 x 239.36 = 35.19 g of PbS.

Answer:

True

Explanation:

The formation of ozone molecules from oxygen molecules is quite a complex radical mechanism, besides, it usually involves the radicals of other gases present in the atmosphere.

Sunlight promotes the formation of these radicals and this is true that in the atmosphere, oxygen is converted into ozone by the following net reaction:

[tex]3 O_2 (g) \rightarrow 2 O_3 (g)[/tex]

The oxygen molecules present in the ocean may have enough kinetic energy to escape the surface of the ocean and reach the atmosphere. When sunlight is used, this conversion from oxygen to ozone becomes possible.

Answer:

474.3 mol

Explanation:

The reaction between sodium bicarbonate and citric acid may be represented by:

[tex]3 NaHCO_3 (aq) + H_3C_6H_5O_7 (aq)\rightarrow Na_3C_6H_5O_7 (aq) + 3 H_2O (l) + 3 CO_2 (g)[/tex]

According to the equation, 3 moles of sodium bicarbonate are required to produce 1 mole of sodium citrate. Let's find the number of moles of sodium citrate as our next step. We'll need its mass and its molar mass.

To find the mass of sodium citrate, we may multiply the density by the volume of the product:

[tex]m_{product} = 1.7 g/ml\cdot \frac{1000 mL}{1 L}\cdot 24 L = 40800 g[/tex]

Dividing this by the molar mass of sodium citrate will produce the number of moles:

[tex]n_{product} = \frac{40800 g}{258.06 g/mol} = 158.1 mol[/tex]

From the stoichiometry of the given equation, we already know that the number of moles of sodium bicarbonate can be found by multiplying the moles of sodium citrate by 3:

[tex]n_{NaHCO_3} = 3\cdot 158.1 mol = 474.3 mol[/tex]

Answer:

848.1 g/mol

Explanation:

Data given:

Standard of atomic mass of Ca = 50 amu

molar mass of Aluminium Acetate = ?

Solution:

Relative atomic mass represented by Ar. It is ratio of actual mass with respect to the 1/12th mass of C-12 but here Ca-50 is standard.

Formula of  Aluminium Acetate = Al(CH₃COO)₃

In order to calculate Ar

first we will calculate 1/50 of Ca

As we know

         mass of 1/12 of C-12 = 1.993 x 10⁻²⁶/12 = 1.661 x 10⁻²⁷ Kg

So, for Ca-50

        mass of 1/50 of Ca-50 = 1.993 x 10⁻²⁶/50 = 3.986 x 10⁻²⁸ Kg

Now

 Relative Atomic mass for element X = rest mass of "X"/ 3.986 x 10⁻²⁸ Kg . . . . . . (1)

First we have to know the relative atomic masses of Aluminium, carbon, hydrogen, oxygen atoms involve in Aluminium Acetate formula with respect to new standard Ca-50

By using equation-1 we can calculate Ar for which we have reported rest masses of atoms as below

Rest mass of Aluminium = 4.48 x 10⁻²⁶ Kg

Rest mass of carbon = 1.993 x 10⁻²⁶ Kg

Rest mass of hydrogen = 1.608 x 10⁻²⁷ Kg

Rest mass of oxygen = 2.657x10⁻²⁶ Kg

Now put values in equation 1 for each atom

                     Ar for Aluminium = 112.5  amu

                     Ar for Carbon= 50 amu

                     Ar for hydrogen = 4  amu

                     Ar for Oxygen = 66.6  amu

Now find the molar mass of Al(CH₃COO)₃

molar mass of Aluminium Acetate = Al(CH₃COO)₃

Al(CH₃COO)₃ = 112.5 + 3 (50 + 3(4) + 50 + 66.6 +66.6)

Al(CH₃COO)₃ = 112.5 + 3 (50 + 12 + 50 + 66.6 +66.6)

Al(CH₃COO)₃ = 112.5 + 3 (245.2)

Al(CH₃COO)₃ = 112.5 + 735.6

Al(CH₃COO)₃ = 848.1 g/mol

molar mass of Aluminium Acetate = 848.1 g/mol

Answer:

[tex]1 Pa\times mm^{2} =10^{-6}Pa\times m^{2}[/tex]

Explanation:

Pascal(Pa) : It is the SI unit of pressure.It is equal to 1 Newton per meter square(Pa =[tex]N/m^{2}[/tex])

[tex]Pa\times mm^{2}[/tex] is the Unit of Force(Newton=N)

Calculation,

It is required to convert [tex]mm^{2}[/tex] to [tex]m^{2}[/tex] only, Pa is same in both so no need to alter Pa.

1 m = 1000 mm (see the image)

And,

1 mm = 0.001 m

[tex]1 mm^{2} = 0.001\times 0.001 m^{2}[/tex] (Squaring both side)

[tex]1 mm^{2} = 0.000001 m^{2}[/tex]

[tex]1 mm^{2} = 10^{-6}m^{2}[/tex]

So,

[tex]1 Pa\times mm^{2} =10^{-6}Pa\times m^{2}[/tex]

Answer:

C)10.7%

Explanation:

24.8-22.4=2.4

22.4→100%

2.4→X%

X=2.4×100/22.4=10.7%

The percent error of the student's measurement, using the correct calculations, is approximately 10.7%.

The percent error is calculated using the formula: percent error = |(experimental value - accepted value)| / accepted value x 100%.

In this case, the accepted value of the molar volume of a gas is 22.4 liters (accepted value), and the student determined the value to be 24.8 liters (experimental value).

Thus, the percent error would be |(24.8 - 22.4)| / 22.4 x 100%, which results in approximately 10.7%. Therefore, the correct answer would be C) 10.7%.

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Answer:

Energy modelling can be described as a system to make simulations or computerized models of systems which use energy. This makes it easier to analyze and access such systems which use energy. By this approach, there are lesser chances for the energy to be wasted and fewer chances for any energy-related experiments to go wrong. As such kind of experiments can be dangerous hence it is essential that models be made first.

Answer:

a. P = 182 atm

Explanation:

Data Given:

amount of CO = 122g

Volume of CO = .400 L

Temperature of CO =  -71.2°C

Convert the temperature to Kelvin

T = °C + 273

T =  -71.2 + 273

T =  201.8 K

a. Calculate the pressure exerted by the CO(g) in this system using the ideal gas equation (P) = ?

Solution:

To calculate Pressure by using ideal gas formula

                  PV = nRT

Rearrange the equation for Pressure

                   P = nRT / V . . . . . . . . . (1)

where

P = pressure

V = Volume

T= Temperature

n = Number of moles

R = ideal gas constant = 0.08206 L.atm / mol. K

For this we have to know the mole of the gas and the following formula will be used

                 no. of moles = mass in grams / molar mass . . . . . . (2)

Molar mass of CO = 12 + 16 = 28 g/mol

Put values in equation 2

                no. of moles = 122 g / 28 g/mol

                no. of moles = 4.4 mol

Now put the value in formula (1) to calculate Pressure for CO

P = 4.4 x 201.8 K x 0.08206 (L.atm/mol. K) / 0.400 L

P = 182 atm

So the pressure will be 182 atm

__________

b. Data Given:

Actual pressure exerted by CO = 145 atm

expected pressure exerted by CO = 182 atm

why the actual pressure is less than what would be expected = ?

Explanation:

This is because of the deviation from ideal behavior of real gases.

The real gases approach to ideal behavior under very high temperature and very low pressure.

But CO deviate from ideal behavior to give expected value for pressure, because it behave at high pressure and low temperature.

This non-ideal behavior is due to two postulate of ideal behavior

but these postulates not obeyed under real condition. so we calculated the pressure using ideal condition values for gas and obtained the expected value for pressure but the actual pressure value was detected under normal condition.

Answer:

most liquids do expand when they freeze

Explanation:

water is actually one that expands and there are probably many more too

i hope this helps you

Final answer:

Water expands when it freezes, which could cause up to 30% of cells to burst in frozen human bodies, thereby posing significant challenges to the concept of cryopreservation. This expansion force also necessitates antifreeze in engines and causes pipes to burst if they freeze.

Explanation:

Most liquids typically contract when they freeze, but water is an exception to this rule. Water expands by about 9% when it freezes, which can lead to significant damage in biological cells. This occurs because ice crystals grow as water solidifies, leading to an increased volume. If human bodies were to be preserved by freezing, the same force that can fracture boulders and engine blocks would cause up to 30% of cells to burst. Consequently, when considering the possibility of preserving human bodies for future revival, extensive cell damage due to the expansion of water upon freezing poses a considerable challenge.

This expansion of water upon freezing underpins the need for antifreeze in engines and the prevention of pipe bursts during cold weather. Furthermore, the unique property of water expanding instead of contracting upon freezing allows ice to float, creating an insulating layer on bodies of water that preserves aquatic life in colder environments.

Answer:

According to the following position vs. Time graph the bicyclist was : D

D. Not moving for the first two seconds, then begin moving at the constant speed.​

Explanation:

[tex]Speed = \frac{Distance}{time}[/tex]

Along Y-axis = Distance in meters

Along X-axis = Time taken in second

Answer:

The correct answer is B reacted chemically.

Explanation:

When a sugar cube in a test tube is heated over a bunsen burner the sugar cube turns back because the heat that is generated by the Bunsen burner dehydrate the sugar molecule.

  As a result the sugar molecule lost water from its chemical structure which causes the sugar molecule to turn black.As water molecules are lost from the sugar the mass of the sugar molecule is being decreased from its original or primary mass.

 In general the sugar molecule undergo dehydration reaction which is responsible for the black coloration of the sugar as well asw los of mass from the sugar molecule.

The sugar cube has undergone a chemical reaction, known as caramelization, when heated over a Bunsen burner. This reaction causes the sugar to turn black and release gases, which reduces its overall mass. The heat change from the Bunsen burner contributes to this chemical process.

When a sugar cube is heated over a Bunsen burner and turns black, it is due to a chemical reaction happening. This process is known as caramelization, where the heat breaks down the sugar molecules into other compounds. This reaction, unlike dissolving sugar in water, is not a physical but a chemical change because it alters the sugar's composition and it cannot be reversed.

The fluffy black mass that forms does indeed have less mass than the original sugar cube. This reduction in mass is due to the release of water vapor and carbon dioxide during the process. These gases escape into the air, lowering the overall mass of the end product.

The heat from the Bunsen burner contributes to this chemical reaction. The heat comes from the combustion reaction of methane under roughly constant atmospheric pressure, making enthalpy a convenient choice for determining the heat changes for such chemical reactions.

Therefore, the correct answer to your question is that the sugar cube has 'reacted chemically' (option B).

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Answer:

C. Gamma > beta > alpha

Explanation:

Alpha rays : These are positively charged  and have mass 4u. These contain high energy Helium nucleus with 2 proton and 2 neutron.

These are heavier and maximum charged than beta and gamma particles.They have low velocity,least penetration power (can't travel more than 10-18 cm).

Beta rays : They are negatively charged and have negligible mass.

On emmission of beta particle, neutron is divided into proton and electron. They have less mass and very high velocity, so their penetrating power is more than alpha particles.

Gamma rays: These are parts of electromagnetic spectrum and travel with the speed of light (maximum velocity).Gamma rays do not have mass have maximum penetrating power.

Answer:

C.  Butanal , is the aldehyde

Explanation:

A . It is carboxylic acid : ---COOH group

B. It is Ester : ----COOR group , Here R = CH3

C. It is Aldehyde : -----CHO group

D. It is ketone : ----C=O group

See image :

Answer:

ΔH°c = - 1605.1 KJ

Explanation:

∴ ΔHf CH4(g) = - 74.6 KJ/mol

∴ ΔHf CO2(g) = - 393.5bKJ/mol

∴ ΔHfH2O(g) = - 241.82 KJ/mol

standard enthalpy of combustion (ΔH°c):

⇒ ΔH°c = (2)(ΔHf H2O) + ΔHfCO2 - ΔHfCH4

⇒ ΔH°c = (2)(- 241.82) + ( - 393.5 ) - ( - 74.6 )

⇒ ΔH°c = - 802.54 KJ/mol

⇒ ΔH°c = ( - 802.54 KJ/mol )(  2 mol CH4 )

⇒ ΔH°c = - 1605.08 KJ

Answer:

C on Edge

Explanation:

Explanation:

you're already have a molarity in Question

Molarity M = numer of moles (n) / Volume (Liter)

first you must convert ml to L > 500 ml = 0.5 L

so 2.2 = n / 0.5

n = 2.2 × 0.5 = 1.1 moles

now you are already have number of moles and from the question you have K2O and you can calculate Molecular weight for K2O

K=39

O=16

Mw = 2×39 + 16 = 94

now you can calculate how gram do you need from

number of mole = mass (g) / molecular weight for k2o

so => 1.1 = mass / 94

mass = 1.1 × 94 = 103.4 g

good luck

Constant and heavy raining can cause the drains to overflow and build up in large puddles.

I have no idea if this is what you were looking for or not.

Answer:

Saturated ground and poor drainage

Explanation:

I did usa prept