Chapter 2 Lesson 1

Question 1

Atom

Element

Answer 1

The smallest basic unit of matter. The consist of protons (+ charge), electrons( -), and neutrons ( no charge)

A substance made of 1 type of atom. Cannot be broken into simpler substances by chemical means

Question 2

Ions

Answer 2

Atoms that have gained or lost electrons
Lose electrons - positively charged
Gain electrons - negatively charged

Question 3

Ionic Bonds

Covalent Bonds

Answer 3

Chemical bonds formed by the transfer of electrons. + and - ions are attracted to each other

Chemical bonds formed when atoms share electrons with other atoms

Question 4

Molecule

Compounds

Answer 4

2 or more atoms held together by covalent bonds

Substances composed of atoms of 2 or more elements ( Example H2O and CO2

Question 5

Polar molecule

Answer 5

Form when atoms in the molecule have unequal pulls on the electrons they share

Question 6

Chemical reactions

Reactants

Products

Answer 6

Change substances into different substances by breaking chemical bonds and forming new chemical bonds. Atoms are rearranged during the process

The initial substances in the reaction

What is formed during the reaction

Question 7

Properties of Hydrogen bonds

Answer 7

Weaker than other covalent bonds but strong enough to influence water molecules

High specific heat

Cohesion - they stick together and it produces surface tension

Adhesion - the attraction among molecules of different substances ( helps plants transport water from the root to the leaves)

Question 8

Solution

Solvent

Solute

Answer 8

Formed when one substance dissolves in another

The substance that is present in the greater amount that dissolves another substance

The substance that is dissolved in a solvent

Question 9

Acid

Base

Answer 9

A compound that releases a proton (+ hydrogen ion ) when it dissolves in water. Adds H ions to a solution

A compound that removes H ions from a solution

***The pH scale is used to measure acidity or the H ion concentration

Question 10

Endothermic Reaction

Exothermic Reaction

Answer 10

When a chemical reaction absorbs more energy than it releases. The products have higher bond energies than the reactants. Usually feel cold

When a chemical reaction releases more energy than it absorbs. The products have lower bond energies than the reactants. Usually feel warm

Question 11

Activation Energy

Catalyst

Answer 11

The amount of energy that needs to be absorbed to start a chemical reaction

A substance that increases the rate of a chemical reaction. They are not changed or consumed during the reaction

Question 12

Enzymes

Answer 12

The catalysts used in living organisms
The structure of enzymes is important because each enzyme’s shape allows only certain reactants to bind to it

Question 13

Cohesion
Adhesion

Answer 13

the attraction among molecules of a substance

the attraction among molecules of different substances