What is the solution to the problem rounded to the correct number of significant figures? 12.77 + .8?

13.6

Explanation:

1- The result should contain the decimal points as the fewest one of the added numbers.

12.77 has two decimals and 0.8 has 1 decimal, so the result should contain 1 decimal.

The result of (12.77 + 0.8) is 13.57.

2- Now, we should minimize the result to contain 1 decimal, so we round the number beside the first decimal (7).

It is higher than 5, so increase the first decimal by 1.

So, the final result is 13.6.

1. 1 mole of anything contains 6.022x10^23 pieces  

d  

2. a  

3. c, number  

5. 1.24x10^24atoms / 6.022x10^23atoms/mole = 2moles h2 atoms  

6. fe2br3 mass = 2moles x mass fe + 3 moles x mass br  

molar mass = grams / number of moles = g/mole  

to find moles = g / molar mass  

to find mass = g = molar mass / moles