Answer:
Explanation:
So basically is just explain what radioacitvity and then radidoactive
Radioactivity is the spontaneous release of energy from an unstable atom to get to a more stable state. Ionizing Radiation is the energy that comes out of a radioactive atom. Radioactive isotopes are radioactive atoms of the same element that have different numbers of neutrons.
Molar mass is the ratio of the mass to that amount of the substance. The mass of the barium nitrate in the formula unit is 23.0 grams.
<h3>What is mass?</h3>
The mass of a substance is the product of the molar mass of the compound and the number of moles of the compound.
Given,
Molar mass of barium nitrate = 261.35 g/mol
If, 
have a mass of 261.35 g/mol then, 
formula units will have a mass of,
Therefore, option C. 23.0 gm is the mass of barium nitrate.
Learn more about mass here:
brainly.com/question/24958554
An Insulator.
Insulators prevent flow of electric current. Example is wood, clay.
The answer is d. particles move from an area of high concentration to low concentration.
