answer: 3.40625 moles
Explanation: see the attached pics
Answer: According to the BBC, the internationally recognized death toll shows that 31 died as an immediate result of Chernobyl. Two workers died at the site of the explosion, another died in hospital soon after due to their injuries and 28 operators and firemen are believed to have died within three months of the accident.
Explanation:
Answer:
Option B is correct.
4
Explanation:
We know that an atom consist of electron, protons and neutrons. Protons and neutrons are present with in nucleus while the electrons are present out side the nucleus.
All these three subatomic particles construct an atom. A neutral atom have equal number of proton and electron. In other words we can say that negative and positive charges are equal in magnitude and cancel the each other. For example, if neutral atom has 6 protons than it must have 6 electrons. The sum of neutrons and protons is the mass number of an atom while the number of protons are number of electrons is the atomic number of an atom.
In given problem we are given with 2 neutrons of helium. We know that the atomic number of He is 2. Thus Mass number of He is,
Number of neutrons + number of proton
2 + 2 = 4
Thus, option B is correct.
