Unit 1: Atomic Structure

Atomic mass

• The mass of an atom of a chemical element expressed in atomic mass units.

• The total number of protons and neutrons in an atom.

• The weight of an atom in grams.

• The mass of an atom relative to the mass of a hydrogen atom.

Tags

NGSS.MS-PS1-5

Electron

• A stable subatomic particle with a charge of negative electricity, found in all atoms and acting as the primary carrier of electricity in solids.

• A positively charged particle found in the nucleus of an atom.

• A neutral particle that contributes to the mass of an atom but has no charge.

• A particle that orbits the nucleus of an atom and has a positive charge.

Tags

NGSS.MS-PS1-1

NGSS.MS-PS2-3

Element

• A pure substance consisting of only one type of atom.

• A mixture of different types of atoms.

• A compound made of two or more elements.

• A solution that contains dissolved substances.

Tags

NGSS.MS-PS1-1

Diatomic

• Elements that consist of three atoms

• Elements found in nature as pairs (consisting of two atoms)

• Elements that are gases at room temperature

• Elements that are metals only

Group

• A row of elements in the periodic table of the chemical elements.

• A column of elements in the periodic table of the chemical elements.

• A type of chemical bond between atoms.

• A classification of elements based on their atomic mass.

Covalent bonding

• A type of bond where electrons are transferred from one atom to another.

• A chemical bond that involves the sharing of electron pairs between atoms.

• A bond that occurs between metal and non-metal atoms.

• A weak interaction between molecules that does not involve electron sharing.

Tags

NGSS.HS-PS1-1

Avogadro’s Number

• Approximately 6.022 x 10^23 particles per mole

• Approximately 3.01 x 10^23 particles per mole

• Approximately 1.20 x 10^24 particles per mole

• Approximately 9.02 x 10^22 particles per mole

Tags

NGSS.HS-PS1-7

Compound

• A substance formed when two or more chemical elements are chemically bonded together.

• A mixture of two or more substances that retain their individual properties.

• A single element that cannot be broken down into simpler substances.

• A solution where one substance is dissolved in another.

Tags

NGSS.MS-PS1-1

Mole

• The amount of substance of a system that contains as many elementary entities as there are atoms in 12 g of carbon-12.

• A unit of measurement for temperature in the metric system.

• The smallest particle of a chemical element that retains its chemical properties.

• A term used to describe the mass of an object.

Tags

NGSS.HS-PS1-7

Atomic number

• The number of neutrons in the nucleus of an atom.

• The number of protons in the nucleus of an atom, which determines the chemical properties of an element and its place in the periodic table.

• The total number of electrons in an atom.

• The mass of an atom measured in atomic mass units.