### SAT - Science - Chemistry - Atomic Structure

#### Question - 1

The number of electrons in the outermost shell and the number of neutrons in the nucleus of $_{ 19 }X^{ 39 }$ are respectively

• A 9,20
• B 1,20
• C 1,19
• D 9,19

#### Question - 2

The total mass of the protons in an atom of an element is 16 u. Atomic number of the element is

• A less than 16
• B greater than 16
• C equal to 16
• D cannot be predicted

#### Question - 3

Identify the correct statement/so

• A $\alpha$ - -particles when combine with two electrons yield Helium gas.
• B $\beta$ -rays are negatively charged particles.
• C $\gamma$ rays are high energy radiations like X-rays
• D All of the above

#### Question - 4

The number of protons, neutrons and electrons in $_{ 35 }Br^{ 80 }$ are respectively

• A 35,45,35
• B 35,35,45
• C 35,35,80
• D 35,80,35

#### Question - 5

The radioactive isotope of hydrogen contains ________ no. of neutrons

• A 0
• B 1
• C 2
• D 3

#### Question - 6

The electronic configuration of an ion X-2 is 2,8,8 If its mass number is 32, the number of protons neutrons and electrons are respectively

• A 18, 14, 18
• B 16,16,16
• C 14,18,24
• D None of these

#### Question - 7

Structures of nuclei of three atoms X, Y and Z are given below.
X has 18 electrons and 22 neutrons
Y has 20 protons and 20 neutrons
Z has 19 protons and 20 neutrons
Based on the above data which of the following statement is correct?

• A X and Yare isotopes, Y and Z are isobars
• B X and Yare isobars, Y and Z are isotopes
• C X and Y are isobars, Y and Z are isotones
• D None of the above

#### Question - 8

Which of the following will have equal number of electrons?
(i)O-2 and F-  (ii) Na+ and Mg2+
(iii) Ar and K+ (iv) Cl and Ar

• A i and ii
• B ii and iii
• C i, ii and iii
• D i,ii,iii and iv

#### Question - 9

Which of the following statement is incorrect about the model of atoms?

• A According to Rutherford's model electrons are moving around the nucleus with high velocity
• B Plum pudding model was proposed by J.J. Thomson
• C According to Bohr's model when an electron revolves in a particular orbit its energy does not change with time
• D Rutherford's model could explain the stability of the atom

#### Question - 10

Identify the wrong statement about cathode rays.

• A These consist of a stream of electrons
• B They are charged particles
• C Can be deflected by electric field
• D They have same velocity as that of light