CHEMISTRY [3 Mark Question Answer]

To find an element inert or not first get atomic number
atomic number = number of proton= (mass-neutron)
A= 4-2=2 so configuration=2
B= 40-22= 18 so configuration =2,8,8
C= 27-13=14 so configuration=2,8,4
D= 20-10=10 so configuration=2,8
Hence A, B and D are inert gases due to octet / duplet rules

List of Monatomic Elements

• helium (He)
• neon (Ne)
• argon (Ar)
• krypton (Kr)
• xenon (Xe)
• radon (Rn)

Atoms of inert gases don’t form molecules. They already have the maximum number of electrons in their outermost shell so, their ionization energy is too high to form a bond with other atoms. That’s why they can’t share, loose or gain electrons to form bond

(a) mass number of P= 13+11=24
(b) mass number of Q= 12+11= 23
(c) Q and P are isotope
(d) Sodium
(e) Metals

Similarities:

1. They all have the same number of protons
2. They all have the same number of electrons
3. They all have the same valence arrangement.
4. They all react the same in chemical reactions

Differences

1. The all have different number of neutrons
2. They all have different atomic weights.
3. They all have different percent abundances.