Groups in Modern Periodic Table

Q.

What is the cause of periodicity?

Q.

Three elements A, B, and C have 3, 4, and 2 electrons respectively in their outermost shell. Give the group number to which they belong in the Modern Periodic Table. Also, give their valencies.

Q.

In the modern periodic table, what remains same down the group?

Q.

Which of the following sets of elements do not belong to the same group?

1. $F,Cl,Br$
2. $Na,K,Rb$
3. $P,S,Cl$
4. $C,Si,Ge$

Q. Elements of a group have similar chemical properties.

1. False
2. True

Q. Which of the following elements shows properties similar to chlorine?

1. Bromine
2. Nitrogen
3. Sulphur
4. Argon

Q. Identify the common property amongst beryllium, magnesium and calcium in the modern periodic table.

1. Same number of electrons in the atom.
2. Same number of electrons in the outermost shell.
3. Same number of shells occupied by the electrons.
4. Their atomic radii is the same.

Q.

All the elements in a particular group have the same ________.

1. Same mass number

2. Same number of valence electrons

3. Different number of valence electrons

4. Same number of shells

Q. The electron affinity of the elements _____ down a group.

1. decreases
2. increases
3. remains same
4. increases or decreases

Q. The chemistry of lithium is very similar to that of magnesium even though they are placed in different groups, because:

1. both are found together in nature.
2. both have nearly the same size.
3. the ratio of their charge to size is nearly the same.
4. both have similar electronic configuration.

Q. All the elements in the same group of the modern periodic table have the same number of valence electrons.

1. True
2. False

Q. How many groups and periods are there in the modern periodic table?

1. 18, 8
2. 18, 7
3. 7, 18
4. 8, 18

Q. An element having electronic configuration 2, 8, 7 will belong to _____ and _____ of modern periodic table.

1. 3rd group & 7th period
2. 17th group & 2nd period
3. 7th group & 3rd period
4. 17th group & 3rd period

Q. (Ex.Q.5)
Write the names and symbols of the constituent elements and identify their valencies from the molecular formulae given below.

${\mathrm{CaCl}}_2,{\mathrm{CCl}}_4,\mathrm{HI},H_{2}S,{\mathrm{Na}}_{2}S,$