The number is written in scientific notation.
The significant figures are the numbers known precisely plus 1 digit that is uncertain.
When the numbers are expressed in scientific notation all the digits before 10^n are significant.
So, 7 and 8 are significant figures and the answer is that the number of significant figures is 2.
Answer: 2
A) 1s on H and 3p on Cl
In HCl, the H atom has only one valance electron. Each share an electron an therefore a single covalent bond is formed between the two. The bond in HCl is therefore a result of an overlap between 1s orbital and ONLY ONE of the lobes of the 3p orbital of Chlorine.