Atoms, Ions, and Isotopes

Flashcards covering key concepts about atoms, ions, and isotopes based on lecture notes.

What is an atom?

The basic unit of matter consisting of a dense nucleus surrounded by negatively charged electrons.

What is the atomic number?

The number of protons in an atom, unique to each element.

What does the mass number represent?

The total number of protons and neutrons in an atom.

In a neutral atom, how are protons and electrons related?

They are equal in number.

What is an ion?

An atom or molecule with an overall positive or negative charge due to an imbalance of protons and electrons.

What does a positive charge on an ion indicate?

It indicates a loss of electrons.

How are ions represented?

With a superscript charge on the element symbol, such as F- or Mg2+.

What are isotopes?

Atoms of the same element that have the same number of protons but different numbers of neutrons.

What does average atomic mass represent?

The average mass of all isotopes of an element found in nature.

How is average atomic mass calculated?

By multiplying the atomic mass of each isotope by its relative abundance and summing the results.

What happens to the number of neutrons in isotopes?

The number of neutrons can vary among isotopes of the same element.

What distinguishes positive ions from negative ions?

Positive ions have lost electrons, while negative ions have gained electrons.

Example: How many protons and electrons does a Cu2+ ion have?

It has the same number of protons as a neutral copper atom and 2 fewer electrons.

What is the average atomic mass for lithium based on its isotopes?

It is the weighted average based on the abundance of Lithium-6 and Lithium-7.