Question

1. what does the 101 in represent?

a. the mass number c. the nuclide number
b. the atomic number d. the number of neutrons

1. most of the volume of an atom is occupied by the

a. nucleus. c. electron cloud.
b. nucleons. d. protons.

1. atoms of the same element can differ in

a. chemical properties. c. atomic number.
b. mass number. d. number of protons and electrons.
matching
match each item with the correct statement below. bubble your choice on your answer sheet.
a. mass number d. atomic mass
b. atomic mass unit e. isotope
c. atomic number

1. atoms with the same number of protons, but different numbers of neutrons in the nucleus of an atom e
2. the total number of protons and neutrons in the nucleus of an atom a
3. the number of protons in the nucleus of an element c
4. the weighted average of the masses of the isotopes of an element b
5. one - twelfth the mass of a carbon atom having six protons and six neutrons d

Explanation:

• Question 7: In the notation \(^{A}_{Z}\text{X}\), \(A\) (the mass number) is written as a superscript. So \(101\) in \(^{101}\text{Md}\) is the mass number.
• Question 8: The electron cloud, which is where electrons are located, occupies most of the atom's volume. The nucleus (containing protons and neutrons - nucleons) is very small.
• Question 9: Atoms of the same element (same atomic number, same number of protons and electrons) can have different mass numbers (due to different numbers of neutrons). These are called isotopes. Chemical properties are mainly determined by the number of electrons (and thus the atomic number), so they are similar for atoms of the same element.
• Question 10: Isotopes are atoms with the same number of protons but different numbers of neutrons.
• Question 11: The mass number (\(A\)) is the total number of protons and neutrons in the nucleus.
• Question 12: The atomic number (\(Z\)) is defined as the number of protons in the nucleus of an element.
• Question 13: The atomic mass is the weighted - average of the masses of the isotopes of an element.
• Question 14: One - twelfth the mass of a carbon atom (\(^{12}\text{C}\)) is defined as an atomic mass unit.

Answer:

1. a. the mass number
2. c. electron cloud
3. b. mass number
4. e. isotope
5. a. mass number
6. c. atomic number
7. d. atomic mass
8. b. atomic mass unit