CHEM Midterm Study Guide

Front

What is the atomic number of an element?

Back

The atomic number is the number of protons in the nucleus of an atom, which determines the element's identity.

Front

How many protons does sodium have?

Back

Sodium has 11 protons.

Front

What does the electron configuration 1s2 2s2 2p6 3s2 3p6 4s2 represent?

Back

This electron configuration represents the element calcium.

Front

How many electrons does silicon (Si) have?

Back

Silicon has 14 electrons.

Front

What happens to the atomic number during alpha decay?

Back

The atomic number decreases by 2 during alpha decay.

Front

What is a cation?

Back

A cation is a positively charged ion, formed when an atom loses one or more electrons.

Front

What is an anion?

Back

An anion is a negatively charged ion, formed when an atom gains one or more electrons.

Front

Define isotope.

Back

Isotopes are atoms of the same element that have the same number of protons but different numbers of neutrons.

Front

What is the significance of the atomic mass?

Back

The atomic mass is the weighted average mass of an element's isotopes, reflecting both the mass and relative abundance of each isotope.

Front

What is the difference between a neutral atom and an ion?

Back

A neutral atom has an equal number of protons and electrons, while an ion has a different number of protons and electrons, resulting in a charge.