Biology Chapter 2

Question 1

Matter

Answer 1

Anything that occupies space and has mass

Question 2

Element

Answer 2

A substance that cannot be broken down to other substances through ordinary chemical means.

Question 3

Compound

Answer 3

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

Question 4

Trace elements

Answer 4

Elects that are essential to the human body but in very minute or small quantities.

Question 5

Atom

Answer 5

The smallest unit of matter that has the properties of an element

Question 6

Proton

Answer 6

Single subatomic particle with a positive charge.

Question 7

Electron

Answer 7

Subatomic particle with a single negative charge.

Question 8

Neutron

Answer 8

Is electrically neutral or has no charge

Question 9

Nucleus

Answer 9

Central core of an atom.

Contains protons and neutrons on the inside

Question 10

Atomic number

Answer 10

Number of protons in an atom of a specific element

Question 11

Mass number

Answer 11

The sum of the protons and neutrons of an atom

Question 12

Atomic mass

Answer 12

It is the total mass of an atom.

The atomic mass approximately equals the mass number

Question 13

Isotopes

Answer 13

One of several forms of an atom. They have the same number of protons and behave identically in chemical reactions, but have a different amount of neutrons.

Question 14

Radioactive isotope

Answer 14

An isotope whose nucleus decays spontaneously, giving off particles and energy.

Question 15

Electron shells

Answer 15

An energy level representing the distance of an electron from the nucleus of an atom

Question 16

Chemical bond

Answer 16

An attraction between two atoms that results from the sharing of electrons or the presence of opposite charges in an atom.

Question 17

Covalent bond

Answer 17

Chemical bond in which one or more pairs of outer shell electrons share

Question 18

Molecule

Answer 18

Two or more atoms held together by covalent bonds

Question 19

Non polar covalent bonds

Answer 19

Chemical bonds in which electrons are shared equally by the atoms of similar Electronegativity

Question 20

Polar covalent bonds

Answer 20

Chemical bonds that have the unequal sharing of electrons that differ in Electronegativity

Question 21

Polar molecule

Answer 21

A molecule containing polar covalent bonds and having an unequal distribution of charges

Question 22

Ion

Answer 22

Is an atom or molecule with an electrical charge

resulting from the gain or loss of electrons

Question 23

Ionic bond

Answer 23

Chemical bond in which a negative atom and a positive atom form a molecule

A chemical bond resulting from the attraction between oppositely charged ions.

Question 24

Salt

Answer 24

A compound resulting from the formation of ionic bonds; also called an ionic compound.

Question 25

Reactants

Answer 25

The starting material in a chemical reaction

Question 26

Product

Answer 26

The ending material in a chemical reaction

Question 27

Chemical reactions

Answer 27

The making and breaking of chemical bonds, leading to changes in the composition of matter.

Question 28

Cohesion

Answer 28

The sticking together of molecules of the same kind, often by hydrogen bonds.

Question 29

Adhesion

Answer 29

The attraction between different kinds of molecules.

Question 30

Surface tension

Answer 30

A measure of how difficult it is to stretch or break the surface of a liquid. Water has a high surface tension because of the hydrogen bonding of surface molecules.

Question 31

Formula for photosynthesis

Answer 31

6CO2(little)+ 6H2O——> C6 H12 O6 + 6O2