What is the energy of red light with a wavelength of 660.5 nm?

Final answer:

A main-group element's lettered group number is closely linked to its valence electrons, with groups 1 and 2 matching the group number and groups 13 to 18 having valence electrons equal to the group number minus ten. Transition metals, found in groups 3-12, do not follow this rule and can have variable valences.

Explanation:

The relationship between a main-group element's lettered group number and its valence electrons is direct and predictable. For elements in groups 1 and 2 (the alkali metals and alkaline earth metals, respectively), the group number is equivalent to the number of valence electrons. For example, elements in group 1 have one valence electron, while those in group 2 have two valence electrons.

When looking at groups 13 to 18, the number of valence electrons is equal to the group number minus ten. Thus, elements in group 13 have three valence electrons, whereas elements in group 14 have four, and so on, with the noble gases in group 18 having eight valence electrons. This relationship helps to determine the chemical properties and reactivities of the elements as they tend to react to achieve a full outer shell of valence electrons, akin to the stable electron configuration of noble gases.

However, this relationship does not apply to the transition metals (groups 3-12), as they may have variable valences. These metals often exhibit multiple possible charges and are identified using Roman numerals in their compound names, such as iron (III) chloride.

I believe that the correct answer among the choices is:

D. The proportion of each element will remain constant, no matter how large or small the volume.

The proportion of the elements is an inherent property of a compound. It can never be changed no matter the size of the compound. This is because the elements are linked by chemical bonds.

Answer:

1: atomic number is 26

2: number of valence electrons is 2

3: number of orbits is 4

4: atomic mass is 56

5: number of neutrons is 30

6: number of electrons in n=3 is 14

Explanation:

Answer: The correct answer is image 1 shows a monomer, and Image 2 shows a polymer.

Explanation:

A monomer is defined as the molecule that react with the same molecule to form a large molecule known as polymer. These are the repeating units in a polymer.

A polymer is a large molecule which are formed when a large number of  same type of molecules react together.

A macro-molecule is defined as a very large molecule such as proteins which are formed by the polymerization of monomers. They are known as natural polymers.

A synthetic polymer are defined as the polymers which are made by humans. They are known as artificial polymers.

In the images given, Image 1 represents a monomer known as ethylene and Image 2 is a polymer known as polyethylene.

Hence, the correct answer is image 1 shows a monomer, and Image 2 shows a polymer,

Answer:the answer is B

Explanation: did the test

First let us calculate the initial molarity of the 2.45 L of solution. Molar mass = 171.34 g/mol

moles Ba(OH)2 = 74.28 g * (1 mole / 171.34 g) =  0.4335 moles

Molarity (M1) = 0.4335 moles / 2.45 L = 0.177 M

Now using the formula M1V1 = M2V2, we can calculate how much to dilute (V1):

0.177 * V1 = 0.1 * 1

V1 = 0.56 L

Therefore 0.56 L of the initial solution must be diluted to 1 L to make 0.1 M

It is true that carbon dioxide can transition from solid to gas directly through sublimation, as seen with dry ice at -78.5°C.

The statement that carbon dioxide can change directly from the solid phase to the gaseous phase is true. This process is known as sublimation. Solid carbon dioxide, also known as dry ice, undergoes sublimation at a temperature of approximately -78.5°C under 1 atmosphere of pressure, transitioning directly from a solid to a gas without passing through the liquid phase. According to the phase diagram of CO₂, the substance cannot exist as a liquid under ambient pressure conditions because its triple point is well above 1 atm. Instead, when warmed, solid CO₂ sublimes, turning directly into a gas.

Final answer:

Dicing potatoes is a physical change since it alters their shape and size but not their chemical identity. This kind of physical change, while being irreversible, does not transform the potatoes into a new substance.

Explanation:

Dicing potatoes is indeed a physical change. This is because when you dice potatoes, you are only changing their shape and size, not their chemical structure or identity. Physical changes can be reversible or irreversible, but they do not alter the fundamental identify of a substance.

Some examples of reversible physical changes include melting, where ice changes to liquid water and can be refrozen, and dissolving, such as when salt is dissolved in water and can be recovered by evaporating the water. Conversely, irreversible physical changes do not easily revert to the original form, such as cutting hair—once it is cut, it cannot grow back instantly.

In the case of dicing potatoes, the physical change is irreversible as you cannot restore the potatoes to their original, uncut state. However, the potatoes remain chemically identical before and after dicing.

1.Nitrogen

7  .Carbon

3.Oxygen

5.Hydrogen

Explanation: I took the test

To see the number of atoms of an element in a given molecule we need to multiply stoichiometry to the number that is written on the foot of the element that is stoichiometry. Therefore, the chemical formula for artificial sweetener is C[tex]_7[/tex]H[tex]_5[/tex]NO[tex]_3[/tex]S.

Atom is the smallest particle of any element, molecule or compound. Atom can not be further divided. Atoms contains nucleus in its center and electron that revolve around the atom in fixed orbit.

In the nucleus, proton and neutron are present. Electron has -1 charge while proton has +1 charge. Neutron is neutral that is it has no charge. So overall the charge of nucleus is due to only proton, not by neutron.

The chemical formula for artificial sweetener is C[tex]_7[/tex]H[tex]_5[/tex]NO[tex]_3[/tex]S.

The number of atoms of Carbon is 7.

The number of atoms of Hydrogen is 5.

The number of atoms of Nitrogen is 1.

The number of atoms of oxygen is 3.

The number of atoms of sulfur is 1.

Therefore, the chemical formula for artificial sweetener is C[tex]_7[/tex]H[tex]_5[/tex]NO[tex]_3[/tex]S.

To know more about atom, here:

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Answer:

Sulfur ₁₆S³²

Explanation:

The sulfur have sixteen protons sixteen neutrons and sixteen electrons. The sum of neutrons and protons is equal to atomic mass. So the given element have sixteen protons and sixteen electron, the atomic mass would be 32 and the element with atomic mass 32 is sulfur.

The number of electrons are equal to the number of protons. In the given element two electrons are more than number of protons. It means element gain two extra electron from another element and it is present in ionic form.

It is present in given form:

S²⁻

Electronic configuration:

S₁₆ = [Ne] 3s² 3p⁴

To complete the octet sulfur gain two electrons from other element and get stable.

Answer:

[tex]^{32}_{16}S^{2-}[/tex]

Explanation:

Atomic number : It is defined as the number of electrons or number of protons present in a neutral atom.

However, when we talk about the atomic number of the ion, it is not equal to the number of electrons as electron can be gained or loosed.

This is why, more appropriately, the number of the protons which are present in the nucleus of the atom is called the atomic number.

Thus, number of protons = atomic number = 16

The element must be sulfur.

Since, number of protons is not equal to the number of electrons, thus the isotope will not be neutral.

There are 2 more electrons than the number of protons and thus, the isotope will be having a charge of -2.

Mass number is the number of the entities present in the nucleus which is the equal to the sum of the number of protons and electrons.

Mass number = Number of protons + Number of neutrons  = 16 + 16 = 32 neutrons

The identity is:- [tex]^{32}_{16}S^{2-}[/tex]

one is air and the other is a liquid 

All isotopes of the same element have the same number of protons. Number of neutrons in different atoms of the same element is free to vary. Since, different elements react differently, different elements have different numbers of protons. Atoms with the same number of protons and vary neutrons behave chemically similar. The number of electrons in a neutral atom depends on the number of protons. All chemical reactions involve transfer or sharing of electrons it stands to reason, neutrons are NOT responsible for chemical reactivity. It's arguable whether protons or electrons dictate chemical reactivity certainly the SUBATOMIC nuclear particle that dictates reactivity is the PROTON.

The Net Ionic equation for the reaction between MgSO4 with Sr(NO3)2 is given by;  

Sr ⁺²(aq) + SO₄⁻²(aq) → SrSO₄(s)

That is:

MgSO₄(aq) + Sr(NO₃)₂(aq) → Mg(NO₃)₂(aq) + SrSO₄(s)

Therefore; the ionic equation required will be;

Sr ⁺²(aq) + SO₄⁻²(aq) → SrSO₄(s)

Level: High school

Subject: Chemistry

Topic: Chemical equation

Sub-topic: Net ionic equations

Answer:

7.859 × 10^-1 g/mL

Explanation:

D=mass/volume

10.782g/13,72ml= 0.78586 g/ml

7.859 x 10^-1 g/ml

IE1 = 578 kJ/mol 

IE2 = 1820 kJ/mol 

IE3 = 2750 kJ/mol 

IE4 = 11600 kJ/mol

If the following set of successive ionization energies are your ionization values this would likely belong to Aluminum. Since there is a huge point between the third and fourth ionization energies, which designates that the atom reached noble gas configuration after the third electron was removed. The element which has 3 valence electrons in the third period is aluminum.

The density of one gold atom is approximately 19.34 g/cm³, calculated by dividing its mass by its volume.

To calculate the density of one gold atom, Need to find its volume and then divide its mass by that volume.

Step 1: Calculate the volume of the gold atom.

The volume of a sphere can be calculated using the formula:

[tex]V_{sphere} = (4/3)\pi r^3[/tex]

Given that the diameter (d) of the gold atom is 272 pm (picometers), you can find the radius (r) by dividing the diameter by 2:

r = 272 pm / 2 = 136 pm = 1.36 x [tex]10^{-8} cm[/tex] (since 1 pm = [tex]10^{-10[/tex] cm)

Now, plug this radius into the formula for the volume of the sphere:

[tex]V_{sphere[/tex] = (4/3)π(1.36 x [tex]10^{-8[/tex] cm)^3 ≈ 1.69 x [tex]10^{-23[/tex] cm^3

Step 2: Calculate the density of one gold atom.

Now that you have the volume of one gold atom, you can calculate its density using the given mass of 3.27 x [tex]10^{-13[/tex] ng (nanograms). First, convert the mass to grams:

1 ng = [tex]10^{-9[/tex] g, so 3.27 x [tex]10^{-13[/tex] ng = 3.27 x [tex]10^{-22[/tex] g

Now, use the formula for density, which is density (ρ) = mass (m) / volume (V):

ρ = (3.27 x [tex]10^{-22[/tex] g) / (1.69 x [tex]10^{-23[/tex] cm^3) ≈ 19.34 g/[tex]cm^3[/tex]

So, the density of one gold atom is approximately 19.34 g/[tex]cm^3[/tex].

Answer:

Intravenous injection.

Explanation:

Injections are the needle used for the transfer of chemicals or drugs from outside environment directly in to the body of an individual. Different body regions are used to inject different drugs depending on their function and mode of action.

Intravenous injections are the needles used to inject the drug directly into the blood stream in the veins and in the muscles. This intravenous injection prevents the over dosage of drugs and proves quite effective in its function.

Thus, the answer is intravenous injection.

Answer:

Explanation:

To determine if the bock will float you need:

The block has 3 dimmentions: lenght, wide and height, its volume is:

[tex]V=wide*lenght*height[/tex]

Once calculated it and measured the  weight, you calculate the density:

[tex]\rho=\frac{m}{V}[/tex]

If the density of the block is smaller than the density of water (arroung 1000 kg/m3) the block will float.

Answer:

Law of definite proportion

Explanation:

A compound is a substance which is composed of two or more elements. According to the law of definite proportion, a compound is made up of element in definite and fixed ratio (by mass) therefore elements in compounds comprises of fixed percent. This law was given by English chemist john Dalton in 1808.