Generally speaking a precipitate is something that will form as a result of the reaction. It generally is a solid material.
Sodium and nitrates are soluble so Calcium Phosphate would precipitate out....
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.
The solid form of a substance is usually more dense than its
liquid and gaseous forms. Similarly the liquid form is usually more dense than
the gaseous form. Ice floating in water is an exception that breaks the general
density rule. So option “A” is the correct option in regards to the given
question. In case of ice formation, actually the density of water decreases by
about 9%. This is the main reason behind ice floating in water. Pure water has
the maximum density at 4 degree centigrade.
I believe it was John Newlands.
Hope that helped
