Atomic Valency

Q. Why do helium, neon and argon have a zero valency?

Q.

Determine the valency of metal and valence electrons with examples.

Q.

Which among the following is not correctly matched?

1. Copper - $\mathrm{Co}$

2. Cobalt - $\mathrm{Co}$

3. Calcium - $\mathrm{Ca}$

4. Silver - $\mathrm{Ag}$

Q.

How is the valency of an atom determined?

Q.

What is the valency of $\mathrm{N}$?

Q. Why do helium, neon and argon have a zero valency?

Q.

Three elements P, Q and R have atomic numbers 4, 12 and 20 respectively

1. State the number of valence electrons in each of these elements
2. Are these elements going to have similar or different chemical properties?
3. Are these elements metals or non-metals?

Q.

What is valency? How is it related to the number of valance electrons?

Q.

Write the chemical symbols for any two elements named after the country where they were discovered.

Q.

Name the elements having the following symbols:

1. Al
2. Cu
3. Mg
4. N
5. Hg
6. P
7. Zn
8. Pb

Q. Hydrogen can be prepared with the help of cold water. Give a reaction of hydrogen with:
$\left(a\right)$ Monovalent atom

Q.

Write the chemical symbols for any two elements named after heavenly bodies.

Q. Explain the difference between valence shell electrons and valency with help of an example ?

Q. Match the elements with their respective number of valence electrons:

1. 4
2. 2
3. 1
4. 6

Q. Question 33
Helium atom has 2 electrons in its valence shell but its valency is not 2. Explain.

Q. The valency of oxygen in $N{a}_2{O}_2$ is :

1. $-2$
2. $+1$
3. $-1$
4. $+2$

Q. Why can there be only 8 electrons in the outermost shell of an elements electronic configuration.

Q.

Define valency by taking example of Silicon and Oxygen.

Q. Atomic number of neon is 10. What is its valency?

1. 0
2. 1
3. 2
4. 3

Q.

What will be the valency of an element having atomic number (Z)=7?

1. 2

2. 1

3. 4

4. 3

Q. The nucleus of an element contains nine protons. Calculate its valency.

Q.

Answer the following question in detail.

Define the following terms:

a) Atom

b) Molecules

c) Radical

d) Valency

Q. The valency of sulphur in sulphuric acid is

1. 2
2. 4
3. 8
4. 6

Q.

Why shoul the penultimate shell have only 8 electrons in some cases?

Q. Which of the following symbols are incorrect? Give the correct symbols for the elements.

Elements	Symbols
a) Cobalt	CO
b) Carbon	C
c) Aluminium	AL
d) Potassium	Po
e) Argon	Ar
f) Sulphur	Sl