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3 years ago

Which is NOT unique to each element?

Chemistry

2 answers:

otez555 [7]3 years ago

7 0

Its B Atomic number

dolphi86 [110]3 years ago

7 0

Answer: The correct answer is Option C.

Explanation:

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

Z = Atomic number = Number of electrons = Number of protons

Mass number is defined as the sum of number of protons and number of neutrons present in an atom. It is represented as A.

A = Mass number = Number of protons + Number of neutrons

For Example: Taking potassium and calcium elements

Number of protons in potassium element = 19

Number of neutrons in potassium element = 20

Number of electrons in potassium element = 19

Number of protons in calcium element = 20

Number of neutrons in calcium element = 20

Number of electrons in calcium element = 20

Neutron number can be same for any two elements.

Hence, the correct answer is Option C.

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Hydrogen gas and aqueous zinc chloride are produced by the reaction of aqueous hydrochloric acid and solid zinc . Write a balanc

Ymorist [56]

1. Write out all the ions/elements and indicate whether they are reactants or products.

Reactants:

Aqueous Hydrochloric Acid: HCl (H has a charge of +1 and Cl has a charge of 1-, so when an ionic bond forms they will form HCl).

Solid Zinc: Zn (since it is a solid zinc with no other forms of elements, the zinc is pure).

Products:

Hydrogen gas: H2 (it has to be H2 because Hydrogen is a diatomic element, and when by itself during reactions, will be H2 instead of H).

Aqueous Zinc Chloride: ZnCl2 (Zn has a charge of 2+ and Cl has a charge of 1-, so through an ionic bond, they will form ZnCl2).

2. Using this information, you can then write out the unbalanced equation.

HCl + Zn -> H2 + ZnCl2

3. Next, indicate their states of matter and any aqueous solutions.

HCl (aq) + Zn (s) -> H2 (g) + ZnCl2 (aq)

4. Try different numbers until you get the same numbers of H, Cl, and Zn on both sides.

2 HCl (aq) + Zn (s) -> H2 (g) + ZnCl2 (aq)

As you can see, the equation contains 2 Hydrogen atoms on both sides, 2 Chloride atoms on both sides, and 1 Zinc atom on both sides. The equation is chemically balanced.

5 0

4 years ago

In the laboratory a student determines the specific heat of a metal. He heats 19.5 grams of copper to 98.27 °C and then drops it

siniylev [52]

Answer:

The specific heat of copper is 0.37 J/g°C

Explanation:

Step 1: Data given

Mass of copper = 19.5 grams

Initial temperature of copper = 98.27 °C

Mass of water = 76.3 grams

Initial temperature of water = 24.05 °C

Final temperature of water and copper = 25.69 °C

Step 2: Calculate specific heat of copper

Qgained = -Qlost

Q = m*c*ΔT

Qwater = -Qcopper

m(water) * c(water) * ΔT(water) = - m(copper) * c(copper) *ΔT(copper)

⇒ with m(water) = 76.3 grams

⇒ with c(water) = 4.184 J/g°C

⇒ with ΔT(water) = T2-T1 = 25.69 - 24.05 = 1.64

⇒ with m(copper) = 19.5 grams

⇒ with c(copper) = TO BE DETERMINED

⇒ with ΔT(copper) = T2-T1 = 25.69 - 98.27 = -72.58

76.3 * 4.184 * 1.64 = - 19.5 * c(copper) * -72.58

523.552 = 1415.31 * c(copper)

c(copper) = 0.37 J/g°C

The specific heat of copper is 0.37 J/g°C

3 0

4 years ago

Ozone (O 3) in the atmosphere can react with nitric oxide (NO): O 3(g) + NO(g) → NO 2(g) + O 2(g). Calculate the ΔG° for this re

Mandarinka [93]

Answer:

ΔG° = 1022. 8 kJ

Explanation:

ΔH° = –199 kJ/mol

ΔS° = –4.1 J/K·mol

T = 25°C = 25 + 273 = 298K (Converting to kelvin temperature)

ΔG° = ?

The relationship between these varriables are;

ΔG° = ΔH° - TΔS°

ΔG° = –199 - 298 (–4.1)

ΔG° = -199 + 1221.8

ΔG° = 1022. 8 kJ

6 0

3 years ago

What stressors will affect the value for Keq according to Le Chatelier's principle?

Goshia [24]

Le Chatelier's principle describes what happens to a system when something momentarily takes it away from equilibrium. If more reactant is added, the equation will shift to the right in order to make more product. If the temperature is decreased, the reaction will shift to the right to create more heat if it is exothermic (which will increase the product), and to the left if it is endothermic (which will decrease the products). If the pressure is decreased, it will shift in the direction where there are more moles of gas present, because it can now take up more space.

3 0

3 years ago

Read 2 more answers

What mass measured in grams of iron would be produced if 4.0 moles of aluminum reacts with an excess of Fe₃O₄? 8Al + 3Fe₃O₄ → 4A

Alecsey [184]

C. 504g that’s the answer

6 0

3 years ago