Development of the atomic model

Question 1

Who proposed the first atomic theory?

Answer 1

John Dalton

Question 2

What year did J.J. Thomson discover the electron?

Answer 2

1897

Question 3

True or False: The plum pudding model describes the atom as a solid positive sphere with electrons embedded in it.

Answer 3

True

Question 4

What experiment did Ernest Rutherford conduct to discover the nucleus?

Answer 4

Gold foil experiment

Question 5

Fill in the blank: The nucleus is made up of ______ and ______.

Answer 5

protons, neutrons

Question 6

What model did Niels Bohr propose in 1913?

Answer 6

Bohr model

Question 7

What is the key feature of the Bohr model?

Answer 7

Electrons orbit the nucleus in fixed paths or energy levels.

Question 8

Who developed the quantum mechanical model of the atom?

Answer 8

Erwin Schrödinger

Question 9

What does the term ‘orbital’ refer to in atomic theory?

Answer 9

A region in an atom where there is a high probability of finding an electron.

Question 10

Which scientist is known for the uncertainty principle?

Answer 10

Werner Heisenberg

Question 11

What is the main difference between the Bohr model and the quantum mechanical model?

Answer 11

The Bohr model has fixed orbits, while the quantum mechanical model has probabilistic orbitals.

Question 12

What did Rutherford conclude about the structure of the atom?

Answer 12

The atom is mostly empty space with a dense nucleus.

Question 13

True or False: The electron cloud model represents electrons as particles in fixed locations.

Answer 13

False

Question 14

What did the discovery of the neutron help to explain?

Answer 14

The stability of the nucleus and isotopes.

Question 15

Who is credited with the first visualization of the electron cloud?

Answer 15

Max Born

Question 16

What does the term ‘isotope’ refer to?

Answer 16

Atoms of the same element with different numbers of neutrons.

Question 17

What key concept did the Rutherford gold foil experiment demonstrate?

Answer 17

The existence of a small, dense nucleus.

Question 18

Fill in the blank: The atomic number is defined as the number of ______ in the nucleus.

Answer 18

protons

Question 19

What element did J.J. Thomson use in his cathode ray tube experiments?

Answer 19

Cathode rays (not a specific element, but he used various gases in tubes)

Question 20

What did Niels Bohr’s model explain about atomic emission spectra?

Answer 20

Electrons emit light when they jump between energy levels.

Question 21

what is the plum pudding model

Answer 21

a cloud of positive charge with negative electrons embedded in it