bio

Element

A substance that cannot be broken down to other substances by ordinary chemical means

Compound

A substance consisting of two or more different elements combines in a fixed ratio

Goiter

a symptom of iodine deficiency that causes the thyroid gland to grow an abnormal size

What is an atomic number?

The amount of protons in an atom

What is a mass number/atomic mass?

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

What is an isotope?

Many different atomic forms of an element that have the same number of protons but a different number of neutrons

What is a radioactive isotope?

An isotope where the nucleus decays spontaneously and gives off particles and energy

What is the outermost electron shell called on an atom?

valence shell

What is it called when two atoms give up, accept, or share electrons with other atoms?

chemical bonds

What is it called when atoms transfer electrons?

ionic bond

What is it called when atoms share electrons?

covalent bond

Molecule

two or more atoms held together by covalent bonds

electronegativity

a measure of an atoms attraction for shared electrons

nonpolar covalent bonds

When two atoms in a covalent bond have the same electronegativity

polar covalent bonds

When two atoms in a covalent bond have different electronegativity

Ion

an atom or molecule with an electrical charge form the gain or loss of electrons

Hydrogen bond

a type of chemical bond formed when a slightly positive hydrogen atom is attracted to a slightly negative atom

polar molecule

a molecule with polar covalent bonds and an unequal distribution of charges throughout it

chemical reactions

breaking chemical bonds and forming new ones

Emergent Properties

many different chemical substances and compounds which can emerge from the most basic chemical substances

Trace Elements

An element essential for life but only needed in small quantities