Intro to Matter

Periods

• Vertical columns on the periodic table.

• Horizontal rows on the periodic table. They are numbered.

• Groups of elements with similar properties.

• Elements arranged by increasing atomic mass.

Homogenous mixture

• Looks the same throughout; uniform.

• Contains different substances that are easily distinguishable.

• Has a variable composition and properties.

• Is a mixture that settles over time.

Molecule

• The smallest part of matter that still retains the characteristics of that particular solid, liquid, or gas.

• A large group of atoms bonded together to form a compound.

• A type of chemical reaction that involves the breaking and forming of bonds.

• A substance made up of only one type of atom.

Electron

• A subatomic particle that has a positive charge; found in the nucleus.

• A subatomic particle that has a negative charge; found in the electron cloud.

• A type of atom that is neutral in charge; found in the nucleus.

• A particle that has no charge and is found in the electron cloud.

Atomic number

• Represents the number of protons in an atom.

• Indicates the total number of electrons in an atom.

• Represents the mass of an atom in atomic mass units.

• Determines the chemical reactivity of an atom.

Element

• A pure substance made of only one kind of atom.

• A mixture of different types of atoms.

• A compound formed by chemical reactions.

• A solution that contains dissolved substances.

The mass of an atom does not include

• Protons

• Neutrons

• Electrons

• Nuclei

Compounds

• A mixture of different substances that can be separated by physical means.

• A new, pure substance made up of elements that are chemically combined.

• A substance that cannot be broken down into simpler substances by chemical means.

• A solution where one substance is dissolved in another.

Water

• A compound, the most common solvent.

• A type of gas found in the atmosphere.

• A solid form of H2O, commonly known as ice.

• A liquid that is not essential for life.

Solid

• A state of matter that has a definite shape and a definite volume.

• A state of matter that flows and takes the shape of its container.

• A state of matter that has no definite shape but has a definite volume.

• A state of matter that can be compressed easily.