Chemistry Flashcard: Average Atomic Mass and Isotopes

Front

What is the definition of isotopes?

Back

Isotopes are variants of a chemical element that have the same number of protons but different numbers of neutrons, resulting in different atomic masses.

Front

How do you calculate the average atomic mass of an element with multiple isotopes?

Back

Average atomic mass = (mass of isotope 1 × abundance of isotope 1) + (mass of isotope 2 × abundance of isotope 2) + ...

Front

What is the isotopic notation for an element with 10 neutrons and 6 protons?

Back

The isotopic notation is Carbon-16 (C-16).

Front

If an atom has an atomic number of 34, what element is it?

Back

The element is Selenium (Se).

Front

What does the atomic number of an element represent?

Back

The atomic number represents the number of protons in the nucleus of an atom.

Front

What is the relationship between protons, neutrons, and electrons in a neutral atom?

Back

In a neutral atom, the number of protons equals the number of electrons.

Front

How many neutrons are in Carbon-14?

Back

Carbon-14 has 8 neutrons (14 - 6 protons = 8 neutrons).

Front

What is the charge of an atom with 34 protons and 36 electrons?

Back

The atom has a charge of -2 (34 protons - 36 electrons = -2).

Front

Calculate the average atomic mass of an element with isotopes of mass 25 amu (70% abundance) and 27 amu (30% abundance).

Back

Average atomic mass = (25 amu × 0.70) + (27 amu × 0.30) = 25.7 amu.

Front

What is the significance of the atomic mass unit (amu)?

Back

The atomic mass unit (amu) is a standard unit of mass that quantifies mass on an atomic or molecular scale.