Explanation:
crystal rocks blue ig
.
Answer:
A and B is the answer as there structure change
There are 0.5 mole in 20g of argon.
40 g of argon = 1mole
Then 20g of argon is,
→ 1/40 × 20
→ 0.5 mole
it is Calcium (Ca)
4th period, 2nd group, 2 valence electrons
molarity
