Arms Staar Science Review 2

Front 1

Exothermic reaction

Back 1

Chemical reaction that releases energy (temperature gets up, increases). ex. combustion.

Front 2

Endothermic reaction

Back 2

Chemical reaction that absorbs energy (temperature gets down, decreases) ex. photosynthesis.

Front 3

Valence Electrons

Back 3

Electrons in the outermost energy level of an atom; they determine an element's chemical properties (reactivity).

Front 4

Metal

Back 4

Element that is malleable, ductile, good conductor of heat and electricity, and generally has a shiny luster.

Front 5

Nonmetal

Back 5

Elements that are usually gases or brittle solids and poor conductors of heat and electricity; are the bases of the chemicals of life.

Front 6

Metalloids

Back 6

Elements that has characteristics of both: metals and nonmetals, solids at room temperature and are semiconductors.

Front 7

Organic Compound

Back 7

Compounds that are usually come organisms. They always have Carbon but may contain other elements like Hydrogen, Oxygen, Nitrogen, Sulfur and Phosphorous. CHON P S

Front 8

Chemical formula

Back 8

A way of describing the number of atoms that makes up one molecule of a compound.

Front 9

Compound

Back 9

A pure substance made of 2 or more elements bonded together chemically, and cannot be separated by chemical means.

Front 10

Chemical reaction

Back 10

Change that takes place when 2 or more substances (reactants) interact to form new substances (products).

Front 11

Chemical equation

Back 11

A way of writing changes in the arrangement of atoms during a chemical reaction, using chemical symbols.

Front 12

Element

Back 12

Natural pure substance that cannot be broken down into simpler materials and has unique properties.

Front 13

Coefficient

Back 13

In a chemical equation, the number placed in front of a chemical formula to balance the equation. Determine the number of molecules.

Front 14

Subscript

Back 14

Is a number that appears smaller than the normal line and indicates the number of atoms of that element in the compound.

Front 15

Reactants

Back 15

Compounds or elements that change during a chemical reaction. Found before the arrow.

Front 16

Products

Back 16

Compounds or elements that are the result of a chemical reaction. Found after the arrow.

Front 17

Chemical digestion

Back 17

Process that uses enzymes to breaks large food molecules into smaller molecules that can be taken in by cells, changing the composition.

Front 18

Mechanical digestion

Back 18

Process of breaking food into smaller pieces by chewing and mashing, without changing the composition.

Front 19

Periodic Table

Back 19

Chart where all the elements are organized into periods and groups according to their properties. Table arranged by atomic number.

Front 20

Periods

Back 20

A row of elements in the Periodic table, elements in the same period share the same number of energy levels.

Front 21

Groups

Back 21

Column of elements in the Periodic table, in which elements have certain properties in common, mainly chemical.

Front 22

Alkaline metals

Back 22

Elements in group 1 in the Periodic table, that are highly reactive metals, and do not occur freely in nature.

Front 23

Halogens

Back 23

5 highly reactive nonmetallic elements found in group 17 of the Periodic table, that are "salt formers".

Front 24

Noble Gases

Back 24

Elements in group 18 with similar properties: odorless, colorless monatomic gases, stable that occur naturally.

Front 25

Atom

Back 25

A very small particle that makes up most kinds of matter and consists of smaller parts called subatomic particles.

Front 26

Atomic number

Back 26

Number of protons in the nucleus of each atom of a given element; the top number in the Periodic table. A

Front 27

Atomic Mass

Back 27

Average mass of an atom of an element; sum of protons and neutrons in an atom. M

Front 28

Proton

Back 28

Positively charge particle located in the nucleus of an atom and that is counted to identify the atomic number. P

Front 29

Neutron

Back 29

Uncharged particle located in the nucleus of an atom. N

Front 30

Electron

Back 30

Invisible, negatively charged particle located in a cloudlike formation that surrounds the nucleus of an atom. E