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.
Answer:
A. The total mass of the reactants in a reaction equals the total mass of the product(s).
Explanation:
The law of conversation of matter tells us that in a chemical reaction, matter is never created or destroyed, it's simply converted from one form to another. So the mass of reactants should always equal the mass of the products in a chemical reaction.
Answer:
All objects resist changes to their states of motion.
Explanation:
Sir Issac Newton was an English physicist, mathematician, astronomer and a well known author. Besides, he was a great scientist. Newton discovered many scientific phenomenon and scientific theories in nature.
The most important and famous discoveries of Newton is the Newton's laws of motion. Newtons stated three laws of motion, namely, Newtons 1st law of motion, Newton's 2nd laws of motion and Newton's 3rd law of motion.
According to Newtons's 1st law of motion : A body continues to be in the state of motion or in the state of rest until and unless an external force is applied to it. In other words, all bodies resists changes to the states of their motion or rest.
You are actually giving 5 points. Ps I just got five points for telling you that