Science 9th grade Chapter 2 vocabulary

Question 0

Nucleus

Answer 0

The center of the atom

Question 1

Atom

Answer 1

Basic unit of matter

Question 2

Electron

Answer 2

Negatively charged particle located outside the atomic nucleus

Question 3

Element

Answer 3

A pure substance that consists of one type of atom

Question 4

Isotope

Answer 4

Atoms of the same element that have different number of neutrons

Question 5

Compound

Answer 5

The substance formed by the chemical combination of two or more elements

Question 6

Ionic bond

Answer 6

Formed when one or more electrons transfer from one atom to another

Question 7

Ions

Answer 7

Positively and negatively charged atoms

Question 8

Covalent bond

Answer 8

When electrons are SHARED between atoms

Question 9

Molecule

Answer 9

Smallest unit of most compounds

Question 10

Van der Waals forces

Answer 10

When molecules are close together, slight attraction develops between the opposite charged regions of molecules

Question 11

Cohesion

Answer 11

An attraction between molecules of the same substance

Question 12

Adhesion

Answer 12

attraction between molecules of different substances

Question 13

Solution

Answer 13

You can see through it, dissolved in water

Question 14

Solute

Answer 14

The substance that is dissolved in a liquid

Question 15

Solvent

Answer 15

The substance in which the solution dissolves, the liquid

Question 16

Suspensions

Answer 16

Not seen through, mixtures of water and undissolved material

Question 17

pH scale

Answer 17

A scale that indicates the concentration of H+ ions in solution

Question 18

Acid

Answer 18

Compound forming H+ ions. Acidic solutions have higher concentrations of H+ ions than pure water. (7 or below on scale)

Question 19

Base

Answer 19

Produces hydroxide ions (OH- ions). Contain lower concentration of
H+ . (Above 7 on scale)

Question 20

Buffers

Answer 20

Weak acids or bases that can react with strong acids or baskets prevent sharp sudden changes in pH

Question 21

Monomers

Answer 21

Small unit that can join together with others to form polymers

Question 22

Polymer

Answer 22

Large compound formed from combinations of many monomers

Question 23

Carbohydrates

Answer 23

Compounds made of carbon, hydrogen, and oxygen

Question 24

Monosaccharides

Answer 24

Single sugar molecules, include galactose, and fractsose

Question 25

Polysaccharides

Answer 25

Large macromolecules formed from monosaccharides

Question 26

Lipids

Answer 26

Made from carbon, and hydrogen atoms. store energy

Question 27

Nucleic acids

Answer 27

Macromolecules containing hydrogen oxygen nitrogen carbon and phosphorus

Question 28

nucleotides

Answer 28

Three parts: 5-carbon sugar phosphate group and a nitrogenous base

Question 29

Ribonucleic acids RNA

Answer 29

Contains sugar ribose

Question 30

DNA

Answer 30

Contains sugar deoxyribose

Question 31

Proteins

Answer 31

Macromolecules that contains nitrogen as well as carbon hydrogen and oxygen

Question 32

Amino acids

Answer 32

Compounds with an amino group ( -NH2) on one end and a carboxyl group (-COOH) on the other end

Question 33

Chemical reaction

Answer 33

A process that changes or transforms one set of chemicals to another

Question 34

Reactants

Answer 34

The elements and compounds that enter into a chemical reaction

Question 35

Products

Answer 35

Elements or compounds produced by a chemical reaction

Question 36

Activation energy

Answer 36

The energy that is needed to start a chemical reaction

Question 37

Catalyst

Answer 37

A substance that speeds up the rate of a chemical reaction

Question 38

Enzymes

Answer 38

Proteins that act as a biological catylist

Question 39

Substrates

Answer 39

The reactants of enzyme-catalyst reactions

Question 40

Mixture

Answer 40

A material composed of two or more elements or compounds that are physically mixed together but not chemically combined