Structure of Atoms

Which of the following correctly represent the electronic distribution in the Mg atom?

• 3, 8, 1

• 2, 8, 2

• 1, 8, 3

• 8, 2, 2

Tags

NGSS.HS-PS1-1

Rutherford’s ‘alpha (α) particles scattering experiment’ resulted into discovery of

• Electron

• Proton

• Nucleus in the atom

• Atomic mass

Tags

NGSS.HS-PS1-8

• 2, 8, 10

• 2, 8, 8, 2

• 2, 8, 2, 8

• 2, 2, 8, 8

Tags

NGSS.HS-PS1-1

Dalton’s atomic theory successfully explained

(i) Law of conservation of mass

(ii) Law of constant composition

(iii) Law of radioactivity

(iv) Law of multiple proportion

• (i), (ii) and (iii)

• (i), (iii) and (iv)

• (ii), (iii) and (iv)

• (i), (ii) and (iv)

Tags

NGSS.HS-PS1-7

Which of the following statements about Rutherford’s model of atom are correct?

(i) considered the nucleus as positively charged

(ii) established that the α–particles are four times as heavy as a hydrogen atom

(iii) can be compared to solar system

(iv) was in agreement with Thomson’s model

• (i) and (iii)

• (ii) and (iii)

• (i) and (iv)

• only (i)

An element has 3 valence electrons in its outermost 3rd shell, the name of element is

• B

• Al

• Ga

• In

Tags

NGSS.HS-PS1-1

If K, L, M N, shells of an atom are full. The total number of electrons in that atom are :

• 60

• 26

• 42

• 36

Tags

NGSS.HS-PS1-1

Na⁺ has 12 neutrons and 10 electrons. Which of the following statement is correct?

• Na⁺ has atomic number equal to 10 and mass number 22

• Na⁺ has atomic number equal to 11 and mass number 23

• Na⁺ has atomic number equal to 10 and mass number 23

• Na⁺ has atomic number equal to 11 and mass number 22

Tags

NGSS.HS-PS1-1

How many electrons, protons and neutrons will be present in X^–, if atomic number of X is 9 and mass number is 19 ?

• E = 9, P = 9, N = 10

• E = 10, P = 9, N = 10

• E = 10, P = 10, N = 10

• E = 9, P = 10, N = 10

Tags

NGSS.MS-PS1-1

Which of the following are true for an element?

(i) Atomic number = number of protons + number of electrons

(ii) Mass number = number of protons + number of neutrons

(iii) Atomic mass = number of protons = number of neutrons

(iv) Atomic number = number of protons = number of electrons

• (i) and (ii)

• (i) and (iii)

• (ii) and (iii)

• (ii) and (iv)