Complete the table given below by identifying P , Q , R and S . Element Symbol No. of Protons No. of Neutrons No. of Electrons Sodium Na 23 11 11 P 11 Chlorine Cl 35 17 Q 18 17 Uranium R 92 146 92 S F 19 9 9 10 9

Element Symbol No. of Protons No. of Neutrons No. of Electrons Sodium Na 23 11 11 12 11 Chlorine Cl 35 17 17 18 17 Uranium U 238 92 92 146 92 Fluorine F 19 9 9 10 9 As we know that A = Z + n , so n = A - Z , A = 23 , Z = 11 so n = 23 - 11 = 12 , Number of neutrons= 12 so p = 12 , Number of protons is equal to the atomic number so Q = 17 . Mass number is Z + n , where Z = Atomic number = number of protons . So R = 92 + 146 = 238 . S = Flourine , because atomic number of fluorine is 9 .

E M B I B E

Concise Chemistry Class 9>Chapter 4 - Atomic Structure and Chemical Bonding>EXERCISE 4(A)>Q 19

EASY

9th ICSE

IMPORTANT

Earn 100

The above sketch is of the model of an atom. (Bohr's / Rutherford's)

50% studentsanswered this correctly

Important Questions on Atomic Structure and Chemical Bonding

EASY

9th ICSE

IMPORTANT

Concise Chemistry Class 9>Chapter 4 - Atomic Structure and Chemical Bonding>EXERCISE 4(A)>Q 20

Give the postulates of Bohr's atomic model.

EASY

9th ICSE

IMPORTANT

Concise Chemistry Class 9>Chapter 4 - Atomic Structure and Chemical Bonding>EXERCISE 4(B)>Q 1

Name the three fundamental particles of an atom.

EASY

9th ICSE

IMPORTANT

Concise Chemistry Class 9>Chapter 4 - Atomic Structure and Chemical Bonding>EXERCISE 4(B)>Q 1

Give the symbol and charge of each fundamental particle of an atom.

EASY

9th ICSE

IMPORTANT

Concise Chemistry Class 9>Chapter 4 - Atomic Structure and Chemical Bonding>EXERCISE 4(B)>Q 2

Complete the table given below by identifying $P, Q, R and S$ .

Element	Symbol	No. of Protons	No. of Neutrons	No. of Electrons
Sodium	${}_{11}{Na}^{23}$	$11$	$P$	$11$
Chlorine	${}_{17}{Cl}^{35}$	$Q$	$18$	$17$
Uranium	$R$	$92$	$146$	$92$
$S$	${}_{9}F^{19}$	$9$	$10$	$9$

EASY

9th ICSE

IMPORTANT

Concise Chemistry Class 9>Chapter 4 - Atomic Structure and Chemical Bonding>EXERCISE 4(B)>Q 3

The atom of an element is made up of

4

protons,

5

neutrons and

4

electrons. What are its atomic number and mass number?

EASY

9th ICSE

IMPORTANT

Concise Chemistry Class 9>Chapter 4 - Atomic Structure and Chemical Bonding>EXERCISE 4(B)>Q 4

The atomic number and mass number of sodium are $11 and 23$ respectively. What information is conveyed by this statement?

EASY

9th ICSE

IMPORTANT

Concise Chemistry Class 9>Chapter 4 - Atomic Structure and Chemical Bonding>EXERCISE 4(B)>Q 5

Write down the names of the particles represented by the following symbols and explain the meaning of the superscript and subscript numbers mentioned.

${}_{1}^{1}P; {}_{0}^{1}n; {}_{- 1}^{0}e$