Chapter 2 quiz

Life is composed of….

matter

>occupies space, has mass

elements are…

unique forms of matter

1. specific chemical properties

2. specific physical properties

4 most common elements of living organisms

Carbon, Oxygen, Nitrogen, and Hydrogen

atom

smallest unit of matter that retains all chemical properties of an element

two regions of an atom

1. nucleus- center of the atom that contains protons and neutrons

2. orbitals- hold electrons around the nucleus

sub-atomic particles

protons, neutrons, and electrons

Atomic Number

the number of protons

Atomic Mass Number

mass of the atom equal to number of protons and neutrons

Isotopes

forms of an element with the same number of protons, but differing numbers of neutrons

calculate the number of neutrons

by
subtracting the atomic number from the atomic mass

Radioisotopes

unstable isotopes that emit neutrons, protons, and electrons

periodic table

shows the atomic mass and atomic number of each element.

Reactants and Products

substances used at beginning of reaction

substances formed at the end of the reaction

Chemical bond

attractive force that links atoms together to form molecules and compounds

Chemical formula

gives the number of each type of atom in a molecule

Structural formula

shows arrangement of atoms in a molecule

COVALENT BONDS

ELECTRONS ARE SHARED

IONIC BONDS

ATOMS GIVE UP OR GAIN ELECTRONS

ion

an atom or group of atoms with a positive or negative charge due to an unequal number of protons (+) and electrons (-).

Electronegativity

The ability of an atom to attract electrons in a chemical bond.

Non-Polar Covalent Bonds

formed when electrons are equally shared by the atoms

Polar Bonds

unequal sharing of electrons

Why is water the most critical molecule for life on earth?

1. It is a polar molecule

2. It can form hydrogen bonds

Three states of water

Liquid water, gas, solid water

Heat capacity

The amount of heat needed to raise the temperature of a substance.

Heat of Vaporization

The heat required to convert a liquid into vapor.

Cohesion

water molecules stick together due to hydrogen bonding

Cohesion allows for… and its definition

Surface Tension: capacity of a substance to withstand being ruptured when placed under tension or stress

Adhesion

An attraction between water molecules and other molecules

Solutions with high H+ concentration

Solutions with high OH- concentration

acidic

alkaline (basic)

Neutral solution has a pH of

Acidic solutions have pH of

Basic solutions have pH of

7

<7

>7

Functional groups often interact with other functional groups by

hydrogen bonding