How many moles are in 1.3 x1023 atoms of He?

Convert .347 kilometers to miles show your work

Suppose that a certain fortunate person has a net worth of $71.0 billion ($7.10×1010). if her stock has a good year and gains $3.20 billion (3.20×109) in value, what is her new net worth?

Comparing john newland’s octaves with the modern periodic table, which 5 elements have been discovered between hydrogen and iron since newland’s time?