A. Li also know as Lithium has 3 protons.
B. To find number of neutrons in a element you subtract number of protons by mass number.
C. Protons have a positive charge.
D. Electrons have a negative charge.
E. Neutrons have no charge and are neutral.
The answer is the 3rd one down I think
The moles are the estimation of the quantities like the molecules and the atoms. There are 7.984 moles of aluminum present in the 2.154 × 10⁻¹ kg substance. Thus, option b is correct.
<h3>What are moles?</h3>
The moles give the estimation of the smaller entities by the ratio of mass or weight to the molar mass of the substance.
The formula for moles is given as,
Moles = mass ÷ molar mass
Given,
Mass of aluminium = 2.154 × 10⁻¹ kg = 2.154 × 10² gm
Molar mass of Al = 26.9 g/mol
Substituting values above:
Moles = 2.154 × 10² gm ÷ 26.9 g/ mol
= 7.984 mol
Therefore, option. 7.984 moles of aluminum are present.
Learn more about moles here:
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Answer:
iron-56
Explanation:
Iron-56 (56Fe) is the most common isotope of iron. About 91.754% of all iron is iron-56. Of all nuclides, iron-56 has the lowest mass per nucleon.
