Question

The mass of Magnesium that contains the same number of atoms as are present in 2g of Calcium is :
(A) 1.2 g
(B) 2.4 g
(C) 0.6 g
(D) 1.8 g

Answer should be (A).​

Answer 1

Answer:

Explanation:

Here's your answer in the pic

Answer 2

Answer-correct option is A

Mass is the quantity of matter in a physical body. It is also a measure of the body's inertia, the resistance to acceleration when a net force is applied. An object's mass also determines the strength of its gravitational attraction to other bodies. The SI base unit of mass is the kilogram.

An atom is the smallest unit of ordinary matter that forms a chemical element. Every solid, liquid, gas, and plasma is composed of neutral or ionized atoms. Atoms are extremely small, typically around 100 picometers across.

Calcium is a chemical element with the symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar to its heavier homologues strontium and barium.

The mole, symbol mol, is the SI base unit of amount of substance. The quantity amount of substance is a measure of how many elementary entities of a given substance are in an object or sample.

Calcium by mole concept

40g of a contains $=6.022\times 10^{23}$ atoms

2g $=\frac{=6.022\times 10^{23}\times 2}{40}$

$=3.011\times 10^22 atoms$

$6.022\times atoms of mg has =24g$

1 atom $=\frac{24}{6.022\times 10^{23}}$

$3.011\times 10^{22}$atoms$=\frac{24}{6.022\times 10^{23}} \times 3.01\times 10^{22}$

$=\frac{12}{10}$

$=1.2g$

Option A

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