Chemistry Chapter 3.1: Electron Theory

Study Notes

Matter and Elements

Matter is defined as anything that occupies space and has weight; examples include air, water, clothing, animals, and the human body.
Matter exists in three primary states: solid, liquid, and gaseous.
An element is a pure substance that cannot be simplified further; examples are gold, silver, oxygen, and iron.
There are over 100 known elements, and all compounds are formed by the chemical combination of one or more elements.
Common compounds include salt (sodium + chlorine) and water (hydrogen + oxygen).
An atom is the smallest particle that retains the characteristics of an element.
Atoms of different elements possess distinct characteristics, leading to the vast diversity in matter.

Diversity of Matter

Similar to how letters combine to form different words, atoms combine in various ways to create a multitude of substances.
The interaction and combination of over 100 elements account for the diverse forms of solid, liquid, and gaseous matter in the environment.

Structure of the Atom

Atoms consist of three subatomic particles: electrons, protons, and neutrons.
Electrons are negatively charged, protons are positively charged, and neutrons carry no charge.
In certain atoms, neutrons may not be present, particularly in hydrogen.
The identity of an atom is determined by the number and arrangement of its subatomic particles.
The variation in the number of subatomic particles distinguishes one element from another.

Description

This quiz covers the fundamentals of electron theory, focusing on the structure and distribution of electrical charges in atoms, molecules, ions, and compounds. Learn about the different states of matter and the definition of elements. Test your understanding of these core concepts in chemistry.