Atomic Theory

Question 1

What is the basic unit of matter?

Answer 1

Atom

Question 2

True or False: An atom can be divided into smaller particles.

Answer 2

False

Question 3

Who proposed the first atomic theory?

Answer 3

John Dalton

Question 4

Fill in the blank: The nucleus of an atom contains ______ and ______.

Answer 4

protons, neutrons

Question 5

What charge do protons carry?

Answer 5

Positive charge

Question 6

What is the relative mass of a neutron compared to a proton?

Answer 6

Approximately the same

Question 7

Which scientist discovered the electron?

Answer 7

J.J. Thomson

Question 8

Multiple Choice: Which of the following particles is negatively charged? A) Proton B) Neutron C) Electron D) Nucleus

Answer 8

C) Electron

Question 9

What did Ernest Rutherford’s gold foil experiment demonstrate?

Answer 9

The existence of a dense nucleus

Question 10

True or False: The atomic number of an element is determined by the number of neutrons.

Answer 10

False

Question 11

What is the atomic number of carbon?

Answer 11

6

Question 12

Fill in the blank: The mass number is the sum of ______ and ______ in the nucleus.

Answer 12

protons, neutrons

Question 13

Who developed the planetary model of the atom?

Answer 13

Niels Bohr

Question 14

What is an isotope?

Answer 14

Atoms of the same element with different numbers of neutrons

Question 15

Multiple Choice: Which of the following statements is true? A) Electrons orbit the nucleus in fixed paths B) Electrons exist in probability clouds C) Electrons are located in the nucleus D) Electrons have a positive charge

Answer 15

B) Electrons exist in probability clouds

Question 16

What is the primary contribution of Dmitri Mendeleev to chemistry?

Answer 16

The creation of the periodic table

Question 17

True or False: All atoms of an element are identical.

Answer 17

False

Question 18

What is the significance of the periodic table?

Answer 18

It organizes elements based on their properties and atomic numbers.

Question 19

Fill in the blank: The number of electrons in a neutral atom is equal to the number of ______.

Answer 19

protons

Question 20

What is the name of the model that describes electron behavior as both particles and waves?

Answer 20

Quantum mechanical model

Question 21

Who proposed the uncertainty principle?

Answer 21

Werner Heisenberg

Question 22

Multiple Choice: Which of the following particles is found in the nucleus? A) Electron B) Proton C) Neutron D) Both B and C

Answer 22

D) Both B and C

Question 23

What is the term for the energy required to remove an electron from an atom?

Answer 23

Ionization energy

Question 24

True or False: An atom’s mass number is always greater than its atomic number.

Answer 24

True

Question 25

What defines the chemical behavior of an element?

Answer 25

The arrangement of electrons

Question 26

Fill in the blank: The ______ theory explains the behavior of gases in terms of particles in constant motion.

Answer 26

Kinetic molecular

Question 27

What is the main difference between a molecule and a compound?

Answer 27

A molecule can consist of the same or different atoms; a compound consists of different atoms.