Question

Astronomy The table shows the mass of the planets, the sum and the moon in our solar system.

Celestial Body	Mass $\left(kg\right)$	Mass $\left(kg\right)$ Standard Notation
Sun	$1,990,000,000,000,000,000,000,000,000,000$	$1.99\times {10}^{30}$
Mercury	$330,000,000,000,000,000,000,000$
Venus	$4,870,000,000,000,000,000,000,000$
Earth	$5,970,000,000,000,000,000,000,000$
Mars	$642,000,000,000,000,000,000,000,000,000$
Jupiter	$1,900,000,000,000,000,000,000,000,000$
Saturn	$568,000,000,000,000,000,000,000,000$
Uranus	$86,800,000,000,000,000,000,000,000$
Neptune	$102,000,000,000,000,000,000,000,000$
Pluto	$12,700,000,000,000,000,000,000$
Moon	$73,500,000,000,000,000,000,000$

Order the planets and the moon by mass, from least to greatest.

Answer 1

In standard form of a number we put decimal after first digit and remaining power is written as power of $10$

So,

Using law of exponents $a^m\times a^n=a^{m+n}$

Sun $=199\times {10}^{28}=1.99\times {10}^{28}\times {10}^2=1.99\times {10}^{30}$

Mercury $=33\times {10}^{22}=3.3\times {10}^{22}\times 10=3.3\times {10}^{23}$

Venus $=487\times {10}^{22}=4.87\times {10}^{22}\times {10}^2=4.87\times {10}^{24}$

Earth $=597\times {10}^{22}=5.97\times {10}^{22}\times {10}^2=5.97\times {10}^{24}$

Mars $=642\times {10}^{27}=6.42\times {10}^{27}\times {10}^2=6.42\times {10}^{29}$

Jupiter $=19\times {10}^{26}=1.9\times {10}^{26}\times 10=1.9\times {10}^{27}$

Saturn $=568\times {10}^{24}=5.68\times {10}^{24}\times {10}^2=5.68\times {10}^{26}$

Uranus $=868\times {10}^{23}=8.68\times {10}^{23}\times {10}^2=8.68\times {10}^{25}$

Neptune $=102\times {10}^{24}=1.02\times {10}^{24}\times {10}^2=1.02\times {10}^{26}$

Pluto $=127\times {10}^{24}=1.27\times {10}^{20}\times {10}^2=1.27\times {10}^{22}$

Moon $=795\times {10}^{20}=7.95\times {10}^{20}\times {10}^2=7.95\times {10}^{22}$

So, by comparing masses in standard form,

we get, Order of mass of all planets and Moon from least to greatest as

$\text{Pluto < Moon < Mercury < Venus < Earth < Uranus < Neptune < Saturn < Jupiter < Mars}$

{Note: Sun is not in a list because it is not a planet or a moon, it is a star.]