Exam 2 chapter 2

Explain Elements

a substance that cannot be broken down to other substances by chemical reactions.

Explain Matter

organisms are composed of matter, which is anything that takes up space and has a mass.

Explain Compounds

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

Explain Atoms

the smallest unit of matter that still remains the properties of an element.

how are they interrelated?

they are all related in ways that they make up all sorts of matter.

What is atom comprised of?

they are composed of even smaller parts called subatomic particles.

Differences between elements and compounds

an element is a substance made of same types of atoms, whereas a compound is made of different elements in definite proportions.

Atomic number

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.

Atomic mass

the mass of an atom of a chemical element expressed in atomic mass units. it is approximately equivalent to the number of protons and neutrons in the atom.

Charges and arrangements of subatomic particles

there are three subatomic particles called electrons, protons, and neutrons. -electrons have a negative charge -protons have a positive charge -neutrons have no change the subatomic particles are held within the atom by one of the four fundamental forces -gravity, electromagnetic force, strong force, and weak force

charges of all subatomic particles

all observable subatomic particles have electric charge on the integer multiple of the elementary charge.

Explain Isotopes

The different atomic forms of the same elements.

Explain Radioactive Isotopes

One in which the nucleus decays spontaneously, giving of particles and energy.

Electron shell arrangements and orbitals

The electrons in an atom are arranged in shells that surround the nucleus, with each successive shell being farther from the nucleus. Electron shells consist of one or more subshells and subshells consist of one or more atomic orbitals.

explain ionic bonding

also called electrovalent bond, type of linkage formed from the electrostatic attraction between oppositely charged ions in a chemical compound.

Explain Polar Covalent

the sharing of a pair of valence electrons by two atoms

Explain Nonpolar covalent

bonds where both atoms possess the same electronegativity, and therefore the electron bond are shared equally between them.

what is the importance of a molecules shape?

the shape of a molecule helps determine its properties

chemical reactions how do we reach chemical equilibrium?

when the rate of the forward reaction is equal to the rate of the backward reaction