Answer:
A
Explanation:
Hundreds of stars
Answer:
The meaning of star system is group of hundreds of stars , that form around the same time .
Explanation:
Which of the following statements is true?
Comet tails always point towards the sun.
Ateroids are made of frozen gas, ice, and water.
Most asteroids are found between Mars and Jupiter.
A light-year is equal to one million miles.
Answer:
your answer is A
Explanation:
Which factors affect electronegativity?
A. Number of electrons and atomic radius
B. Number of unshielded electrons and density of the element
C. Atomic radius and number of unshielded protons
D. Density of the element and atomic radius
Answer:
I guess it would be C.
Explanation:
because it sounds familiar
How many grams are 1.20x10^24 atoms of potassium.
Answer:
77.9
Explanation:
how many grams of acetylene are produced by adding 3 moles of cac2
Answer:
78.12g of acetylene
Explanation:
Acetylene and calcium hydroxide are produced when H₂O reacts with CaC₂. The reaction is:
2 H₂O + CaC₂ → C₂H₂ + Ca(OH)₂
Where 1 mole of C₂H₂ (acetylene) is produced per mole of CaC₂
Thus, the addition of 3 moles of CaC₂ produces 3 moles of acetylene.
As molecular mass of acetylene is 26.04g/mol, grams of acetylene produced are:
3mol C₂H₂ × (26.04g / mol) = 78.12g of acetylene
Final answer:
By adding 3 moles of calcium carbide, you will produce 78.12 grams of acetylene, as the reaction yields a 1:1 mole ratio and acetylene has a molar mass of 26.04 g/mol.
Explanation:
To answer the question of how many grams of acetylene are produced by adding 3 moles of calcium carbide (CaC₂), we will refer to the chemical reaction:
CaC₂ (s) + 2 H₂O(l) → C₂H₂(g) + Ca(OH)₂ (s).
According to the balanced chemical equation, 1 mole of calcium carbide reacts with water to produce 1 mole of acetylene. Therefore, if you start with 3 moles of calcium carbide, you will produce 3 moles of acetylene. The molar mass of acetylene (C₂H₂) is approximately 26.04 g/mol. Consequently, to find the mass of 3 moles of acetylene we calculate:
3 moles C₂H₂ × 26.04 g/mol = 78.12 grams of acetylene.
So, by adding 3 moles of calcium carbide, you will produce 78.12 grams of acetylene.
(3x^4)^4 I need the steps to
Answer:
81 x ^16
Explanation:
PEMDAS
You need to do parenthesis
What is a disadvantage of using solar energy to produce electricity
Answer:
Sun
Explanation:
It Might be raining meaning that the sun isn't shining very brightly.
Answer:
The solar energy might cost a lot in order to install it. As well, there is no solar power at night so you won't have the electricity you need. So like in winter in some place there is no Sun, more specifically the light from the Sun, it is sometimes cloudy all day and there is no light coming from the Sun, so like I said you won't have electricity.
Explanation:
I hope my explanation was understandable :/
Maria needs to dilute her stock of 15.0 M HNO3 solution for a lab. She wants to get 525 mL of 1.00 M HNO3. How many mL of 15.0 HNO3 must she prepare?
Answer:
35
Explanation:
I got it wrong and it gave me the right answer.
The concentration terms are molality, normality and mole fraction. Molarity can be used to find out the ionic strength of any solution. Therefore, 35ml of 15.0 HNO3 must she prepare.
What is molarity?Molarity can be calculated by dividing number of moles of solute by volume of solution in litre. Molarity is affected by temperature. Its unit is mole/liter. It measure the concentration of any solute in a solution.
Mathematically,
According to the dilution law,
M₁V₁=M₂V₂
where, symbols have following meaning
M₁ = molarity of stock solution = 15.0 M
V₁ = volume of stock solution =?
M₂ = molarity of dilute solution =1.00M
V₂ = volume of dilute solution = 525 mL
substituting all the given values we get
M₁V₁=M₂V₂
15.0×V₁=1.00×525
V₁=35ml
Therefore, 35ml of 15.0 HNO3 must she prepare.
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According to the equation, 2 H2 + O2 --> 2 H20, how many moles of oxygen are required to convert 12 moles of hydrogen to water?
Answer:
6 moles of oxygen, or 3O2.
Explanation:
I would build a proportion for this:
[tex] \frac{2(2)}{2} = \frac{12}{x} \\ 4x = 24 \\ x = 6[/tex]
How many grams of HF are needed to react with 3.0 moles of Sn? *
How many moles of SnF₂ will be produced along with 48 grams of H₂? *
Sn + 2HF (arrow) SnF2 + H2
30g
60g
120g
240g
Answer:
60 g
Explanation:
if element x forms the oxides xo and x2o3 the oxidation numbers of element x are
a)+1 and +2
b)+2 and +3
c)+1 and +3
d)+2 and +4
Answer:
b) +2 and +3.
Explanation:
Hello,
In this case, given the molecular formulas:
[tex]XO[/tex]
And:
[tex]X_2O_3[/tex]
We can relate the subscripts with the oxidation states by knowing that they are crossed when the compound is formed, for that reason, we notice that oxygen oxidation state should be -2 for both cases and the oxidation state of X in the first formula must be +2 since both X and O has one as their subscript as they were simplified:
[tex]X^{+2}O^{-2}[/tex]
Moreover, for the second case the oxidation state of X should be +3 in order to obtain 3 as the subscript of oxygen:
[tex]X_2^{+3}O_3^{-2}[/tex]
Thus, answer is b)+2 and +3
Best regards.
In the case when the element x forms the oxides xo and x2o3 the oxidation numbers of element x are option b +2 and +3.
Calculation of the number of elements:
The equation should be X2O3.
Here we can link the subscripts with the oxidation states by knowing that they should not be linked at the time when the compound should be formed. So here the oxygen oxidation state should be -2 and the oxidation state of x should be +2.
Its like
X+2O-2
Here in the second case, the oxidation state of x should be +3 for obtaining 3 and treated as the subscript of oxygen.
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The compound ammonia is composed of a single nitrogen atom bonded by single bonds to three hydrogens. How many electrons total are contained in the three single bonds?
A. 3
B. 4
C. 5
D. 6
D)6 electrons are contained in the three single bonds.
Is ammonia a hydrogen bond?An ammonia molecule can donate and be given up to a few hydrogen bonds. Ammonia clusters are made out of ammonia molecules connected via hydrogen bonds. The hydrogen bond community of ammonia clusters is related to ammonia's homes.
The bond formed via Nitrogen and Hydrogen is a covalent bond because each is non-metal. While those two atoms bond, Nitrogen nonetheless has an excess of 2 valence electrons which might be called the “lone pair”.
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What is a way that we can slow down climate change?
A. Use alternative energy sources such as coal, which produce less carbon dioxide than fossil fuels.
B. Fly less often as planes make as much greenhouse gas as 3 months of driving would.
C. Cut down trees on our property which produce carbon dioxide.
D. Reduce visiting the beach, the heavy foot traffic releases carbon dioxide stored in the sand.
Answer:
I would guess B, because trees make oxygen, not carbon dioxcide, and coal is actually a very harmful source of energy.
hope this helps
Explanation:
Final answer:
To slow climate change, it is crucial to reduce energy use, switch to alternative energy sources like solar and wind, and enhance carbon sinks by planting forests.
Explanation:
To slow down climate change, we should focus on several key actions. First, we need to reduce energy use, which could include measures like turning off lights when not in use and driving more fuel-efficient cars. These steps help because much of the electricity and transportation relies on burning fossil fuels, which releases large amounts of carbon dioxide.
Another important action is to switch to cleaner alternative energy sources, such as solar, wind, and geothermal energy. These sources produce little to no carbon emissions compared to fossil fuels like coal, oil, and natural gas. Additionally, increasing the use of technologies like hybrid cars can drastically reduce air pollution and fossil fuel consumption. Moreover, we can combat climate change by enhancing carbon sinks, such as planting more forests which absorb carbon dioxide from the atmosphere.
A mixture of oxygen, hydrogen and eater vapor has a total pressure of 684 mm Hg. The partial pressure of oxygen is 380 mm Hg and that of hydrogen is 0.100 atm. That is the partial pressure of the water vapor?
Answer:
684 mmHg
Explanation:
A mixture of oxygen, hydrogen and water vapor has a total pressure of 684 mm Hg, then the partial pressure of water vapor is 228 mmHg.
What is Dalton's Law?Dalton's law of gases states that total pressure of the mixture of gases is equal to the sum of the partial pressure of each gases present there, i.e.
P = p₁ + p₂ + p₃, where
P = total pressure of gas = 684 mmHg
p₁ = partial pressure of oxygen = 380 mmHg
p₂ = partial pressure of hydrogen = 0.100 atm = 76 mmHg
p₃ = partial pressure of water vapor = ?
On putting values, we get
p₃ = 684 - (380 + 76)
p₃ = 228 mmHg
Hence required partial pressure of water vapor is 228 mmHg.
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(PLS HELP I HAVE 5 MINS TO TURN IN)
The parts that are either directly or indirectly related to each other in a system are known as what?
A)the input
B)the components
C)the boundary
D)the flow
Answer:
im guessing D
Explanation:
hope it helps
what is the organization that regulates the safety of Bluetooth and other wireless devices
Answer:
The U.S. Federal Communications Commission (FCC)
Explanation:
The FCC's Wireless Telecommunications Bureau regulates the safety and policies of Bluetooth and other wireless devices, while the FDA's Center for Devices and Radiological Health oversees the safety of radiation-emitting products, including Bluetooth-enabled devices.
The organization primarily responsible for the regulation of Bluetooth and other wireless devices in the United States is the Federal Communications Commission (FCC), specifically through its Wireless Telecommunications Bureau (WTB). The WTB handles all FCC wireless telecommunications programs and policies, which includes a variety of services such as amateur radio, cellular networks, pagers, Personal Communications Service (PCS), and more. They work to manage and license the radio frequencies and provide policies to ensure the safety and reliability of wireless communication services.
On the other hand, for devices that emit radiation, including Bluetooth-enabled devices, the Center for Devices and Radiological Health (CDRH), a division of the Food and Drug Administration (FDA), oversees the performance and safety of these products. This includes a broad range of items from medical devices to non-medical radiation-emitting products, ensuring that both medical and consumer devices adhere to safety standards.
a sample of gas has a volume of 5.79 L at 25C and 518. What will be the volume of this gas at STP
Answer:
V2 = 389mL
Explanation:
At STP: P=760 torr and T=273K.
To solve this question, we could use Charles' law since both the number of mole and pressure are constant:
V1T1=V2T2
⇒V2=T2×V1T1
⇒V2=273K×425mL/298K=389mL
Explain why iodine is brittle in its solid state
Final answer:
Solid iodine is brittle due to weak dispersion forces between iodine molecules in its molecular lattice structure, which when stressed can cause layers to shift and fracture.
Explanation:
Iodine is brittle in its solid state because of its molecular lattice structure, where individual iodine molecules are held together by relatively weak dispersion forces. Despite being the strongest within the halogen group, these forces are not strong enough to allow for flexibility, so when iodine crystals are subjected to mechanical stress, layers of molecules can shift, leading to fracture and resulting in the brittleness observed. Iodine's electron configuration, with -empty valanced orbitals, allows for these molecular interactions to occur in its solid state.
Why is sodium hydrogen carbonate an effective antacid but sodium hydroxide is not?
Hydrogen peroxide, Hoz, is common in many households and is used as a bleaching agent. It usually comes in a dark, opaque bottle. When exposed to heat or light, hydrogen peroxide will decompose according to the reaction:
2H2O2--->2H2O+O2
Iron Nitrate has been shown to be an effective catalyst to accelerate the decomposition process and sodium phosphate can inhibit the effects of this catalytic effect.
Naturally, the consumer does not want their hydrogen peroxide to decompose Consider the factors affecting reaction rate that you learned about in this lesson. What should the consumer should do to prevent the decomposition of hydrogen peroxide? For example, should the hydrogen peroxide be stored in a warm or cool location? Use scientific reasoning to support your response
Answer:
1) hydrogen peroxide should be stored in dark bottles away from light
2) hydrogen peroxide should be stored in a cool place.
3) Drops of sodium phosphate may be added to inhibit its catalytic decomposition
Explanation:
Hydrogen peroxide is known to dissociate according to the equation;
2H2O2--->2H2O+O2.
This decomposition is facilitated by the following factors;
1) heat
2) light
3) presence of trace amounts of a catalyst
This implies that, if the user stores the hydrogen peroxide in a dark bottle, away from sunlight. It decreases its chances of decomposition.
Similarly, if the hydrogen peroxide bottle is stored in a cool environment, it is not decomposed by heat.
Lastly, drops of an inhibitor such as sodium phosphate may be added to inhibit the effect of any catalyst that may have mistakenly contaminated the hydrogen peroxide sample.
why do you say that is the right answer
Answer:
because it is
Explanation:
Answer:
it is
Explanation:
it just is wym
4) Determine the Celsius temperature of 2.49 mol of gas contained in a 2.00-L vessel at a
pressure of 143 kPa.
Answer:
The temperature of the gas contained in the container is -259.35° C
Explanation:
To find the unit of degrees in Celsius (° C) in this case, the ideal gas law equation is used.
PV = nRT
Where P is the pressure, V is the volume, T is the temperature, n is the number of moles, and R is the universal gas constant.
P = 143kPa = 1.4113 atm V = 2.00L n = 2.49 mol R = 0.08205746 atm * L / mol * KSolving for T would be: PV / nR
T = ( 1.4113 atm * 2.00 L ) / ( 2.49 mol * 0.08205746 atm * L / mol * K )
T = 2.8226 / 0.2043
T = 13.8K = -259.35 ° C
Answer:
The Celsius temperature of the gas is -259.34 ° C
Explanation:
To answer the question, we note that the universal gas equation can be expressed as follows;
P·V = n·R·T
Therefore;
[tex]T = \frac{P \cdot V}{R \cdot n}[/tex]
Where:
n = Number of moles = 2.49 mol
P = Pressure = 143 kPa = 143000 Pa
V = Volume = 2.00 L = 0.002 m³
T = Temperature in Kelvin, K = Required
R = Universal Gas Constant = 8.3145 J/(mol·K)
Plugging in the values, we have;
[tex]T = \frac{143000 \times 0.002 }{8.3145 \times 2.49 } = 13.81 \, K[/tex]
Hence the temperature of the gas = 13.81 K
Converting the Kelvin temperature to Celsius temperature, we have
Celsius temperature = Kelvin temperature - 273.15
Therefore, 13.81 K to Celsius temperature gives;
13.81 - 273.15 = -259.34 ° C.
Which of the following statements is true?
Evaporation is the main way water enters the atmosphere.
Condensation is the opposite of evaporation.
The total amount of water on the earth stays the same.
all of the above
Answer:
Evaporation is the main way water enters the atmosphere.
Explanation:
Evaporation is the main way moisture enters the atmosphere. The amount of evaporation is not the same all of the world. Most evaporation happens over large bodies of water, like oceans and seas. Very little evaporation happens in dry areas, such as deserts. The amount of water on earth is constant. This means it does not change.
PLEASE HELP
What type of patterns can a tidal height graph show ?
Answer:
Diurnal, Semidiural and mixed
When pentane (C5H12) mixes with heptane (C7H16), what type of intermolecular forces must be broken? What type of attractive forces are formed?
A) Dipole-dipole; dispersion
B) Dipole-dipole; Dipole-dipole
C) Dispersion; Dipole-dipole
D) Dispersion; dispersion
Answer:
D) Dispersion; dispersion
Explanation:
Pentane or heptane are non-polar molecules so both of the , dispersion or london force exists as intermolecular force exists among molecules of pentane or heptane . So these bonds needs to be broken and dispersion interaction takes place between molecules of pentane and heptane. Dispersion interaction of AB type is stronger than AA or BB type.
Mixing of nonpolar molecules pentane and heptane results in the breaking and forming of dispersion forces, which are intermolecular forces present in such hydrocarbons.
Explanation:When pentane (C5H12) and heptane (C7H16) mix, the type of intermolecular forces that must be broken are dispersion forces. Both pentane and heptane are nonpolar molecules hence the only intermolecular forces present are the weak dispersion forces or London dispersion forces. These are the instantaneous dipole-induced dipole forces that result from transient shifts in electron density. The somewhat stronger intermolecular force among nonpolar hydrocarbons is basically due to larger electrong cloud, and the only type of 'attractive forces' available for them to form when they mix are still the same - dispersion forces
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what is the chemical equation in words for 2 C2H2 (g) + 5 O2 (g) ---------> 4 CO2 (g) + 2 H2O (l )
Answer:
Ethyn(g) + 5oxygen(g) ------------> 4carbondioxide(g) + 2water(l)
What determines an object's potential energy?
Answer:
potential energy of an object depend on three factors. If an object has less mass,it will travel more distance, and Higher the mass of an object Distance tra
Explanation:
Which atoms combine together during fusion reaction on the sun?
Answer:
Hydrogen
Explanation:
Four hydrogen atoms combine together during fusion reaction on the sun. In the core of the Sun hydrogen is being converted into helium.
What is fusion ?Fusion is the process by which the sun and stars are powered. It is the reaction in which two hydrogen atoms combine or fuse to form a helium atom. Some of the hydrogen's mass is converted into energy during the process.
The Sun and other stars are powered by nuclear fusion reactions. A fusion reaction occurs when two light nuclei combine to form a single heavier nucleus.
When two atoms collide, they fuse to form a heavier atom, such as when two hydrogen atoms fuse to form one helium atom. This is the same process that powers the sun and generates enormous amounts of energy many times more than fission.
Thus, Four hydrogen atoms combine together during fusion reaction on the sun.
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What type of bond would form between two atoms of selenium?
A. Single ionic bond
B. Double covalent bond
C. Double ionic bond
D. Single covalent bond
Answer:
the correct answer is B
hope it helps !!!
When harmful bacteria invade a wound, the skin around the wound turns red. This is known as:
Answer:
Inflammation
Explanation:
Inflammation is the response to a cut. The blood vessels expand when you get cut to allow white blood cells to flock to the wound site. These attack any bacteria that got past the clot. If you mean excess bacteria, then that would be an infection.
The redness around a wound caused by harmful bacteria is due to inflammation, an immune response that involves blood vessel dilation, increased blood flow, and white blood cells combatting the infection.
Explanation:When harmful bacteria invade a wound, the skin around the wound turns red due to a process called inflammation. This biological response is the body's second line of defense against pathogens. Inflammation is triggered by the release of chemicals when skin or other tissues are damaged. These chemicals cause blood vessels to dilate, increasing blood flow and making the area red and warm.
The influx of blood also delivers white blood cells like neutrophils to the wound site, and these cells help to combat the bacterial invaders. A well-known agent in this process is histamine, which not only contributes to the dilation of blood vessels but also helps attract immune cells to the site of injury. This inflammatory response helps to establish a physical barrier against the spread of infection and begins the process of tissue repair.
need help QUICK...
Which of the following is a compound?
lithium
carbon dioxide
potassium
nitrogen
Answer:
nitrogen
Explanation: