Answer:
easy
Explanation:
c.
the pressure of the air above the substance.
Answer:
Kinetic energy , is the energy of an object possessed due to it's motion
Explanation:
Kinetic energy is the energy of mass in motion. The kinetic energy of an object is the energy it has because of its motion.
it's formula ½mv²
Answer:
He supported the ideology of Marxism.
He opposed the tsar and was exiled.
He led the Bolsheviks.
Explanation:
Lenin was Russian Revolution political theorist. He served as first founding head of government of Soviet Russia. He supported the ideology of Marxism and opposed Tsar.
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.
