Question

How many moles of calcium atoms do you have if you have 3.00 × 10²¹ atoms of calcium. (The mass of one mole of calcium is 40.08 g.)

Answer 1

Answer:

0.0050moles

Explanation:

Since

1 mole=6.022×10^23

X mole=3.0×10^21

Cross multiply

6.022×10^23x=3.0×10^21

Divide both sides by 6.022×10^23

x=0.00498~0.0050moles

So the final answer is 0.0050moles

Answer 2

Answer:

4.98x10^-3 mole

Explanation:

According to Avogadro's hypothesis, 1 mole of any substance contains 6.02x10^23 atoms. This greatly implies that 1 mole of calcium will also contain 6.02x10^23 atoms.

Now, if 1 mole of calcium contains 6.02x10^23 atoms,

then Xmol of calcium will contain 3x10^21 atoms i.e

Xmol of calcium = 3x10^21/6.02x10^23

Xmol of calcium = 4.98x10^-3mol

Therefore, 4.98x10^-3 mole of calcium contains 3x10^21 atoms