One uranium atom has a mass of 3.95 x 10^-22 grams.
a) work out an estimate for the number of uranium atoms in 1kg
b) is your answer to (a) an underestimate or an overestimate?
give reason for your answer.

!

Remember
(ab)/(cd)=(a/c)(b/d)
and


1kg=1000g=1*10^3g
hmm, I estimate, 4 of them

x=number of attoms
mass of 1 times x=1*10^3
3.95*10^-22 times x=1*10^3
divide both sides by 3.95*10^-22
x===
a million has 9 zeroes
so 24 zeroes is alot that is a septillion, so there are 2.5316 septillion uranium atoms in 1kg

a. 4
b. underestimate

54.49, 54.48, 54.47.

If the number after the tenth is 5 or above, that number changes to 0 and disappears, and it makes the tenth one bigger number.