All categories

3 years ago

It is possible for a particular element to have various numbers of neutrons. True False

Chemistry

1 answer:

umka2103 [35]3 years ago

7 0

Answer:

True

Explanation:

Every element is constituted by atoms with the same atomic number, which is the number of protons in their nuclei. So, all the atoms of a same element have the same number of protons.

For instance, the element sodium has atomic number 11, and all its atoms have 11 protons.

The atomic number identifies uniquely every element.

In the atomic nuclei there are protons and neutrons. Neutrons can vary from one atom of a particular element to another atom of the same element. That is what the term isotope accounts for. Isotopes are atoms with the same atomic number and different number of neutrons.

Most elements have different isotopes. The atomic mass of fifferent isotopes of a particular element will differ among them, because the neutrons account for the mass.

You might be interested in

Which notation represents the largest atomic radius?

Darina [25.2K]

Answer:

Calcium(Ca)

Explanation:

Atomic radius is the distance from the nucleus of an atom the outermost energy shell or energy level.
The atomic radii of metals are greater than the ionic radii since metals form ions by losing electrons.
Calcium atom has a larger atomic radius compared to magnesium atom because it has more energy levels. Calcium atoms have four energy levels while magnesium atoms have three energy levels.

7 0

3 years ago

1 pentagram equals how many grams

Fofino [41]

Answer:

5 grams.

Explanation:

Anything that weighs 5 grams, technically, is a pentagram.

7 0

3 years ago

3.) All matter has both physical and chemical properties. A physical property is one that does not change the chemical nature of

dexar [7]

Answer:

Explanation:

It would be D because you are observing the reaction and don’t change anything

8 0

2 years ago

In the laboratory, a general chemistry student measured the pH of a 0.486 M aqueous solution of triethanolamine, C6H15O3N to be

STatiana [176]

Answer:

Kb = 6.22x10⁻⁷

Explanation:

Triethanolamine, C₆H₁₅O₃N, is in equilibrium with water:

C₆H₁₅O₃N(aq) + H₂O(l) ⇄ C₆H₁₅O₃NH⁺(aq) + OH⁻(aq)

Kb is defined from concentrations in equilibrium, thus:

Kb = [C₆H₁₅O₃NH⁺] [OH⁻] / [C₆H₁₅O₃N]

The equilibrium concentration of these compounds could be written as:

[C₆H₁₅O₃N] = 0.486M - X

[C₆H₁₅O₃NH⁺] = X

[OH⁻] = X

pH is -log [H⁺], thus, [H⁺] = 10^-pH = 1.820x10⁻¹¹M

Also, Kw = [OH⁻] ₓ [H⁺];

1x10⁻¹⁴ = [OH⁻] ₓ [H⁺]

1x10⁻¹⁴ = [OH⁻] ₓ [1.820x10⁻¹¹M]

5.495x10⁻⁴M = [OH⁻], that means X = 5.495x10⁻⁴M

Replacing in Kb formula:

Kb = [5.495x10⁻⁴M] [5.495x10⁻⁴M] / [0.486M-5.495x10⁻⁴M]

Kb = 6.22x10⁻⁷

5 0

3 years ago

Copper metal (Cu) reacts with silver nitrate (AgNO3) in aqueous solution to form Ag and Cu(NO3)2. The balanced chemical equation

Rufina [12.5K]

The mass formed in a chemical reaction is given by stoichiometry law in balanced chemical equation. The mass of silver produced in the reaction is 107. 9 g.

<h3>What is the stoichiometric law?</h3>

The stoichiometric law states that in a balanced chemical equation, the stoichiometric coefficient describes the moles of each compound in a chemical reaction.

The balanced chemical equation for the reaction is:

$\rm Cu\;+\;2\;AgNO_3\;\rightarrow\;Cu(NO_3)_2\;+\;2\;Ag$

From the balanced chemical equation, 1 moles of copper results in 2 moles of silver.

Moles in terms of mass can be given as:

$\rm Moles=\dfrac{Mass}{Molar\;mass}$

Thus, moles of 31. 75 grams copper is:

$\rm Cu=\dfrac{ 31. 75 }{63.5}\;mol\\ Cu=0.5 mol$

The moles of Ag produced can be given from stoichiometric law as:

$\rm 1\;mol\;Cu=2\;mol\;Ag\\0.5 \;mol\;Cu=0.5\;\times\;2\;mol\;Ag\\0.5\;mol\;Cu=1\;mol\;Ag$

The moles of Ag produced is 1 mol.

The mass of a mole of element is equivalent to the molar mass. Thus, the mass of Ag produced in the reaction is 107. 9 g. Hence, option B is correct.

Learn more about stoichiometric law, here:

brainly.com/question/6907332

7 0

2 years ago