Chemistry: States of Matter and Atoms

Study Notes

State of Matter

Matter is composed of substance
Substance is made of Compound
Compound is made of Molecules
Molecules are made of elements
Elements are made of Atoms
A bond is a smaller unit of an atom
A group of atoms which are not combined with bonds are called elements
A group of molecules is called a compound
Hydrogen exists as H₂ (molecule)
A group of molecules called a compound

Atoms

Atoms are the smallest unit of an element
An atom consists of protons (p), neutrons (n), and electrons (e)
Protons and neutrons are found in the nucleus (center of the atom).
Electrons orbit the nucleus.
Protons have a positive charge, neutrons have no charge and electrons have a negative charge.
Atoms have equal numbers of protons and electrons, making them electrically neutral in their natural state.
Atomic number is the number of protons in the atom's nucleus
Atomic mass (or weight) is the total number of protons and neutrons in the nucleus
Examples: Hydrogen (H), Sodium (Na)

Molecules

Molecules are formed when two or more atoms are bonded together
Molecules can be made up of the same type of atom or different types
Molecules are held together by chemical bonds
Ex: H₂ (hydrogen molecule)

Compounds

Compounds are formed when two or more different types of atoms combine chemically
Compounds are formed from molecules
In a compound, the ratios of atoms are fixed

Ions

Atoms can gain or lose electrons, becoming electrically charged particles
Positively charged ions are called cations
Negatively charged ions are called anions
Gaining or losing electrons alters the charge of an atom without changing the number of protons or neutrons

Description

Explore the essential concepts of matter, compounds, and atomic structure in this chemistry quiz. Learn about the composition of substances, the role of molecules, and the properties of atoms, including protons, neutrons, and electrons. Test your understanding and reinforce your knowledge of these fundamental scientific principles.