The mass number of an element tells us the number of protons AND neutrons in an atom (the two particles that have a measurable mass). Sodium has a mass number of 23amu. Since sodium has 11 protons, the number of neutrons must be 23 – 11 = 12 neutrons.
A sort of electricity is a light bulb or a phone / computer charger. plants food water. the sun and rain . that’s what i’m guessing!
Mass= density x volume
1.3 kg/m^3 x ( 2.5x4x10) m^3
= 130 kg
Answer:
B
Explanation:
did this yesterday with my friend
The sentences are invalid and unsound.
<h3><u>Explanation</u>:</h3>
The fire is defined as the vigorous oxidation of a substance. Now oxidation can occur in presence of any oxidising agent. Like magnesium in presence of nitrogen in high temperature with a dazzling brownish flame to produce magnesium nitride. So fire can be produced in absence of oxygen.
Oxygen is present everywhere in world. So production of a whole room without oxygen is very tough to produce and costly process. So its very unsound.