Chapter U1.12, Problem 8E

Interpretation Introduction

Interpretation:

Elements from lowest number of protons to highest number of protons are to be arranged. Information such as name, atomic number, number of protons, number of electrons and group number about each atom is also to be given.

Concept introduction:

The periodic table is an organized chart of elements. The elements are arranged in groups and periods based on the similarities in their physical and chemical properties. Modern periodic table is a storehouse of information about the elements. The number of vertical columns is 18 which are called groups and there are 7 horizontal rows known as periods. Elements in the middle of the periodic table are not very reactive.

Each element square contains information such as element name, symbol, atomic number and average atomic mass.

Answer to Problem 8E

The following table shows elements arranged in order of their increasing number of protons. Other information about the elements is also given.

Chemical symbol	Name of element	Atomic number	Number of protons	Number of electrons	Group number
N	Nitrogen	7	7	7	15
Na	Sodium	11	11	11	1
Mg	Magnesium	12	12	12	2
S	Sulfur	16	16	16	16
Se	Selenium	34	34	34	16
Sr	Strontium	38	38	38	2

Explanation of Solution

Given information: The following symbols of elements are given.

S, Mg, Na, N, Se, Sr

From the periodic table we get the following information about elements:

Element name, symbol, atomic number and average atomic mass

Each square of the periodic table looks like the one given below:

Atomic number gives the number of protons which is also equal to the number of electrons.

1. Symbol - N - (given)
Element name - Nitrogen (from the periodic table)

Atomic number - 7 (from the periodic table)

Number of protons = atomic number = 7

Number of electrons = atomic number = 7

Group number-15 (from the periodic table)

2. Symbol - Na - (given)
Element name - Sodium (from the periodic table)

Atomic number - 11 (from the periodic table)

Number of protons = atomic number = 11

Number of electrons = atomic number = 11

Group number-1 (from the periodic table)

3. Symbol - Mg - (given)
Element name - Magnesium (from the periodic table)

Atomic number - 12 (from the periodic table)

Number of protons = atomic number = 12

Number of electrons = atomic number = 12

Group number-2 (from the periodic table)

4. Symbol - S - (given)
Element name - Sulfur (from the periodic table)

Atomic number - 16 (from the periodic table)

Number of protons = atomic number = 16

Number of electrons = atomic number = 16

Group number-16 (from the periodic table)

5. Symbol - Se - (given)
Element name - Selenium (from the periodic table)

Atomic number - 34 (from the periodic table)

Number of protons = atomic number = 34

Number of electrons = atomic number = 34

Group number-16 (from the periodic table)

6. Symbol - Sr - (given)
Element name −Strontium (from the periodic table)

Atomic number - 38 (from the periodic table)

Number of protons = atomic number = 38

Number of electrons = atomic number = 38

Group number-2 (from the periodic table)

Nitrogen has the least number of protons (7) whereas strontium has highest number of protons (38)

Conclusion

The periodic table gives us information such as element name, symbol, atomic number and average atomic mass. Number of protons is equal to number of electrons and is known as atomic number.