Question

SCIENCE AND TECHNOLOGY - ACTIVITY II
1) The atomic mass and atomic number of an atom is given.
27
13
A = 27 z = 13
a) Find number of neutrons in its nucleons?
b) Write its electronic configuration.
c) Discuss its valency.
2) a) Define Valency.
b) Valency of Chlorine is 1 though it has 7 valence electrons.
3) a) What is atomic radius?
b) Is the atomic radius of Hydrogen or Helium the smallest.
He
State the name of the lightest element and element with smallest radius.
c) H
4) Calculate molecular mass of Calcium hydroxide.
[Atomic mass: Ca - 40,0 - 16, H - 1]
5) a) State the law of conservation of matter.
b) Name the scientist who put forth this law.
6) How many molecules of water are there in 36 gms of water? class 9 pls answer​

Answer 1

Answer:

5.a.

The Law of Conservation of Mass

Matter can change form through physical and chemical changes, but through any of these changes, matter is conserved. The same amount of matter exists before and after the change—none is created or destroyed. This concept is called the Law of Conservation of Mass