How much would 2.25*10^25 atoms of carbon weigh

Question

An atom of carbon weighs about 2*10^-26

 

 

 

 

Answer 1

To multiply using scientific notation, you multiply the numbers and the exponents separately.

 

2.25 × 10²⁵ atoms * 2 × 10^-26 g/atom

= (2.25 * 2) × (10²⁵ * 10^-26) g

= 4.5 × 10^-1 g

 

To write this as a standard number, move the decimal point -1 places (1 to the left <- )

= 0.45 g

Answer 2

The molar mass of carbon is 12.011 g.

 

So, 6.022 x 10²³ atoms of carbon have a mass of 12.011 g.

 

 

Mass of 2.25 x 10²⁵ C atoms:

 

(2.25 x 10²⁵)(12.011 / 6.022 x 10²³) = 449 g

 

 

Or, using the given information,

 

(2.25 x 10²⁵)(2 x 10^-26) = 0.45 kg = 450 g