Question

The mass of the Earth is about 6,000,000,000,000,000,000,000,000 kg. The mass of a human toddler's brain is about 400 grams. SHOW ALL WORK

(a) What is the mass of the Earth written in scientific notation?
(b) What is the mass of a toddler’s brain in scientific notation?
(c) In comparing the measurements in Parts (a) and (b), what else must be done before a comparison is made?
(A) = 6 x 10^24
(B) = 4 x 10^2
(C) but i need help on C cause I think you have to combine the kg and grams but I dont know how

Answer 1

Explanation:

that's why it is so important to always write also the units a number represent.

and for a fully nice scientific notation you write also at least 1 digit after the decimal point.

(a) 6.0 × 10²⁴ kg

(b) 4.0 × 10² g

now,

1 kg = 1000 g ("kilo" means 1000)

so, in order to be able to compare the 2 numbers, you have to bring both numbers to the same unit. either both to kg or both to g.

6.0 × 10²⁴ kg = 6.0 × 10²⁴ × 1000 g = 6.0 × 10²⁷ g

or

4.0 × 10² g = 4.0 × 10² / 1000 kg = 4.0 × 10^-1 kg

once you have both showing the same unit, you can truly compare them.