Earth and Space Science Chapter 4

Compound

two or more elements combined chemically

Molecule

group of atoms held together by chemical forces

Chemical equations

A representation of a chemical reaction that uses symbols to show the relationship between the reactants and the products

Chemical bonds

forces that hold together the atoms in molecules

Ion

charged particle

Ionic bond

transfer of electrons

Covalent bond

sharing of electrons

Polar covalent

unequal sharing ex) water

Mixtures

combo of two or more substances not chemically combined (heterogeneous and homogeneous)

Alloy

solution of two or more metals ex) steel

Chemical properties

characteristics that describe how a substance reacts with other substances to make new substances

ion

atom or molecule that has a negative or positive charge

isotope

atom with the same number of protons but a different number of neutrons as other atoms of the same element

neutron

subatomic particle that has no charge, located in the nucleus

electron

subatomic particle that has a negative charge

atomic mass unit (amu)

unit of measure for the mass of subatomic particles

Physical properties

characteristics that can be observed without changing the substance

Atomic number

the number of protons in the nucleus of an atom

Proton

subatomic particle that has a positive charge

mass number

the sum of the number of protons and neutrons in an atom

in order of atomic number

What is one way elements in the periodic table are arranged?

proton, neutron, electron

What are the three major types of subatomic particles?

They have similar arrangements of electrons.

What is true of elements in the same column on the periodic table?

a substance made of chemically bound atoms of two or more different elements

What is a compound?

by sharing or transferring electrons

How do atoms form chemical bonds?

a solution of two or more metals

What is an alloy?

two atoms of oxygen

What does the subscript mean in the chemical formula CO2?

atom

What is the smallest unit of an element that keeps all of the chemical properties of a substance?

It is stable.

What is true of an atom with 8 valence electrons?

two or more substances not chemically combined

What is a mixture?