Answer:
A = The central core and is composed of protons and neutrons.
Explanation:
An atom consist of electrons, protons and neutrons. The neutrons and protons are present inside the nucleus, which is central core of atom and have positive charge. While electron is 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 electron is subatomic particle that revolve around outside the nucleus and has negligible mass. It has a negative charge.
Symbol= e-
Mass= 9.10938356×10-31 Kg
It was discovered by j. j. Thomson in 1897 during the study of cathode ray properties.
While neutron and proton are present inside the nucleus. Proton has positive charge while neutron is electrically neutral. Proton is discovered by Rutherford while neutron is discovered by James Chadwick in 1932.
Symbol of proton= P+
Symbol of neutron= n0
Mass of proton=1.672623×10-27 Kg
Mass of neutron=1.674929×10-27 Kg
Mass % of NaCl = 0.9 % (m/v)
Density of 0.9 % NaCl is about 1.0 g/mL
Volume of NaCl in mL :
= 11.25 mL NaCl
Answer:
Volume of HBr = V₂ = 7.5 mL
Explanation:
Given data:
Volume of NaOH =V₁= 25.0 mL
Molarity of NaOH =M₁= 0.150 M
Molarity of HBr =M₂= 0.5 M
Volume of HBr =V₂= ?
Solution:
M₁V₁ = M₂V₂
0.150 M ×25.0 mL = 0.5 M×V₂
V₂ = 0.150 M ×25.0 mL / 0.5 M
V₂ = 3.75 M.mL /0.5 M
V₂ = 7.5 mL
Answer:
4s2
Explanation:
The electronic configuration of zinc in the ground state of the atom is 1s22s22p6 3s23p63d104s2. It can be written in a condensed form by showing the inert gas core as follows; [Ar] 3d¹⁰ 4s².
Zinc has a pseudo inert gas configuration when the 4s electrons are removed during oxidation. Hence this sublevel is usually affected when zinc atoms are oxidized according to the scheme;
Zn---->Zn^2+ + 2e-