All the members of group 15 have ……………. electrons in their outermost orbit.

1. 3
2. 7
3. 5
4. 8

Which of the following statements is correct with respect to the elements — Na, Mg, Al, Si, P, S and Cl.

1. Each element belongs to the same group.
2. Valency of each element is the same.
3. Each element belongs to the same period.
4. They are all metals.

Elements which have their outermost orbits incomplete are:

1. Transition elements
2. Noble gases
3. Inner transition elements
4. Representative elements

The element with atomic number 16 is placed in the modern periodic table in:

1. 2nd period and VI A group
2. 3rd period and IV A group
3. 3rd period and VI A group
4. 2nd period and IV A group