Neutrons.
Not sure if you need a full explanation but let me know if you do :]
Explanation:
30 lb is 480 ounces
34 mi/second is 54.718 kilometre/ second
455 lb/ gal is 54521.024 grams / litre
50 cl is 500 millilitres
55nm is 5.5 × 10^-6 centimetre
Answer: 97
Explanation:
The element Ru is <u>Ruthenium</u> which has <u>44 protons</u>.
In this case, our atom is an isotope with <u>53 neutrons</u>.
With this information, we can use the mass number formula to find this atom's mass number.
mass number = protons + neutrons
mass number = <u>44 protons</u> + <u>53 neutrons</u>
mass number = <u>97</u>
It is going through a physical change