Chemistry: Atomic Theory Quiz 1a

1. A positively charged subatomic particle is

Proton

Mass Number

Element Number

Neutron

A positively charged subatomic particle is a proton. Protons are found in the nucleus of an atom and have a positive charge. They are one of the fundamental particles that make up an atom, along with neutrons and electrons. Protons have a mass number of 1 and an element number that determines the type of element they belong to.

Explanation

A positively charged subatomic particle is a proton. Protons are found in the nucleus of an atom and have a positive charge. They are one of the fundamental particles that make up an atom, along with neutrons and electrons. Protons have a mass number of 1 and an element number that determines the type of element they belong to.

2. Atoms with the same number of protons but different numbers of neutrons are:

Isotopes

Protrons

Relative Abundance

Neutrons

Atoms with the same number of protons but different numbers of neutrons are called isotopes. Isotopes have the same atomic number (number of protons) but different mass numbers (sum of protons and neutrons). This means that isotopes of an element have the same chemical properties but different physical properties, such as atomic mass. Isotopes can have different stability and may undergo radioactive decay.

Explanation

Atoms with the same number of protons but different numbers of neutrons are called isotopes. Isotopes have the same atomic number (number of protons) but different mass numbers (sum of protons and neutrons). This means that isotopes of an element have the same chemical properties but different physical properties, such as atomic mass. Isotopes can have different stability and may undergo radioactive decay.

3. He said that the atom resembles a tiny rock.

Thomson

Bohr

Democritus

Dalton

Democritus is the correct answer because he was the first to propose the idea of atoms. He believed that atoms were indivisible and indestructible particles that make up all matter. By comparing atoms to tiny rocks, he was emphasizing their solid and fundamental nature. Thomson, Bohr, and Dalton also made significant contributions to atomic theory, but Democritus was the first to suggest the existence of atoms.

Explanation

Democritus is the correct answer because he was the first to propose the idea of atoms. He believed that atoms were indivisible and indestructible particles that make up all matter. By comparing atoms to tiny rocks, he was emphasizing their solid and fundamental nature. Thomson, Bohr, and Dalton also made significant contributions to atomic theory, but Democritus was the first to suggest the existence of atoms.

4. Choose the statement that is FALSE.

None of them below

Electrons have the mass of 1 amu

Protons have the mass of 1amu

Neutrons have the mass of 1 amu

The statement "electrons have the mass of 1 amu" is false. Electrons have a much smaller mass compared to protons and neutrons. In fact, the mass of an electron is approximately 1/1836 amu, which is significantly lighter than 1 amu.

Explanation

The statement "electrons have the mass of 1 amu" is false. Electrons have a much smaller mass compared to protons and neutrons. In fact, the mass of an electron is approximately 1/1836 amu, which is significantly lighter than 1 amu.

5. A subatomic particle with no charge is:

Proton

Electron

Neutron

Some type of "tron"

An electron is a subatomic particle with no charge. It is negatively charged and orbits around the nucleus of an atom. Protons, on the other hand, carry a positive charge, while neutrons have no charge at all. The option "Some type of 'tron'" is not a valid subatomic particle and does not exist.

Explanation

An electron is a subatomic particle with no charge. It is negatively charged and orbits around the nucleus of an atom. Protons, on the other hand, carry a positive charge, while neutrons have no charge at all. The option "Some type of 'tron'" is not a valid subatomic particle and does not exist.