Chapter U1, Problem 3RE

Interpretation Introduction

(a)

Interpretation:

Periodic table must be used to find the atomic symbol, atomic number, group number, number of protons and number of electrons in lithium.

Concept introduction:

In periodic table, elements are arranged in increasing order of the atomic number. There are 18 groups and 7 periods in the periodic table.

Explanation of Solution

Lithium is a metal with 1 valence electron and atomic number 3 as it belongs to group 1 of the periodic table. So, number of electrons and protons are both 3.

Thus,

Atomic symbol of lithium is Li.

Atomic number is 3.

Group number is 1.

Number of protons is 3.

Number of electrons is 3.

Interpretation Introduction

(b)

Interpretation:

Periodic table must be used to find the atomic symbol, atomic number, group number, number of protons and number of electrons in bromine.

Concept introduction:

In periodic table, elements are arranged in increasing order of the atomic number. There are 18 groups and 7 periods in the periodic table.

Explanation of Solution

As bromine is a non-metal with 7 valence electrons and atomic number 35 so number of electrons and protons are both 35.

Thus,

Atomic symbol of bromine is Br.

Atomic number is 35.

Group number is 17.

Number of protons is 35.

Number of electrons is 35.

Interpretation Introduction

(c)

Interpretation:

Periodic table must be used to find the atomic symbol, atomic number, group number, number of protons and number of electrons in zinc.

Concept introduction:

In periodic table, elements are arranged in increasing order of the atomic number. There are 18 groups and 7 periods in the periodic table.

Explanation of Solution

As zinc is a metal with 2 valence electrons in d block and has atomic number 30 so number of electrons and protons are both 30.

Thus,

Atomic symbol of zinc is Zn.

Atomic number is 30.

Group number is 12.

Number of protons is 30.

Number of electrons is 30.

Interpretation Introduction

(d)

Interpretation:

Periodic table must be used to find the atomic symbol, atomic number, group number, number of protons and number of electrons in sulfur.

Concept introduction:

In periodic table, elements are arranged in increasing order of the atomic number. There are 18 groups and 7 periods in the periodic table.

Explanation of Solution

As sulfur is a non-metal with 6 valence electrons in p block and atomic number is 16 so number of electrons and protons are both 16.

Thus,

Atomic symbol of sulfur is S.

Atomic number is 16.

Group number is 16.

Number of protons is 16.

Number of electrons is 16.

Interpretation Introduction

(e)

Interpretation:

Periodic table must be used to find the atomic symbol, atomic number, group number, number of protons and number of electrons in barium.

Concept introduction:

In periodic table, elements are arranged in increasing order of the atomic number. There are 18 groups and 7 periods in the periodic table.

Explanation of Solution

As barium is a metal with 2 valence electrons in s block and atomic number is 56 so number of electrons and protons are both 56.

Thus,

Atomic symbol of barium is Ba.

Atomic number is 56.

Group number is 2.

Number of protons is 56.

Number of electrons is 56.

Interpretation Introduction

(f)

Interpretation:

Periodic table must be used to find the atomic symbol, atomic number, group number, number of protons and number of electrons in carbon.

Concept introduction:

In periodic table, elements are arranged in increasing order of the atomic number. There are 18 groups and 7 periods in the periodic table.

Explanation of Solution

As carbon is a non-metal with 4 valence electrons in p block and atomic number 6 so number of electrons and protons are both 6.

Thus,

Atomic symbol of carbon is C.

Atomic number is 6.

Group number is 14.

Number of protons is 6.

Number of electrons is 6.