chemistry ch 4 study

Question 1

Atom

Answer 1

a particle of matter that uniquely defines a chemical element.

Question 2

atomic mass

Answer 2

the quantity of matter contained in an atom of an element.

Question 3

atomic number-

Answer 3

the number of protons in the nucleus of an atom.

Question 4

chemical bond

Answer 4

the physical phenomenon of chemical substances being held together by attraction of atoms to each other through sharing, as well as exchanging, of electrons -or electrostatic forces.

Question 5

chemical change

Answer 5

a change of materials into another, new materials with different properties and one or more than one new substances are formed.

Question 6

chemical formula

Answer 6

shows the elements that make up the compound and the numbers of atoms of each element in the smallest unit of that compound

Question 7

chemistry

Answer 7

a science that deals with the composition, structure, and properties of substances and with the transformations that they undergo.

Question 8

compound

Answer 8

something formed by a union of elements or parts especially : a distinct substance formed by chemical union of two or more ingredients in definite proportion by weight a new antibiotic compound.

Question 9

covalent bond

Answer 9

the mutual sharing of one or more pairs of electrons between two atoms. These electrons are simultaneously attracted by the two atomic nuclei. A covalent bond forms when the difference between the electronegativities of two atoms is too small for an electron transfer to occur to form ions.

Question 10

double bond

Answer 10

a chemical bond in which two pairs of electrons are shared by two atoms in a molecule — compare single bond, triple bond.

Question 11

electrons

Answer 11

a negatively charged subatomic particle that can be either bound to an atom or free (not bound).

Question 12

element

Answer 12

a substance that cannot be broken down into simpler components by any non-nuclear chemical reaction.

Question 13

heterogeneous mixtures

Answer 13

is a mixture in which the composition is not uniform throughout the mixture.

Question 14

homogeneous mixtures

Answer 14

the types of mixtures in which the components mixed are uniformly distributed throughout the mixture.

Question 15

inorganic compounds

Answer 15

any substance in which two or more chemical elements (usually other than carbon) are combined, nearly always in definite proportions.

Question 16

ionic bond

Answer 16

a chemical bond formed between oppositely charged species because of their mutual electrostatic attraction.

Question 17

law of conservation of matter

Answer 17

The amount of matter stays the same, even when matter changes form.

Question 18

matter

Answer 18

substance made up of various types of particles that occupies physical space and has inertia.

Question 19

mixtures

Answer 19

the act of combining

Question 20

molecule

Answer 20

The smallest particle of a substance that has all of the physical and chemical properties of that substance.

Question 21

neutrons

Answer 21

A neutron is a subatomic particle found in the nucleus of every atom except that of simple hydrogen.

Question 22

nucleus

Answer 22

the membrane-enclosed organelle within a cell that contains the chromosomes.

Question 23

orbitals

Answer 23

a mathematically described region around a nucleus in an atom or molecule that may contain zero, one, or two electrons

Question 24

organic compounds

Answer 24

any of a large class of chemical compounds in which one or more atoms of carbon are covalently linked to atoms of other elements, most commonly hydrogen, oxygen, or nitrogen.

Question 25

phase change

Answer 25

when matter changes to from one state (solid, liquid, gas, plasma) to another.

Question 26

physical change

Answer 26

A change in matter which does not alter the chemical properties of the matter.

Question 27

products

Answer 27

the number or expression resulting from the multiplication together of two or more numbers or expressions.

Question 28

protons

Answer 28

a subatomic particle found in the nucleus of every atom.

Question 29

reactants

Answer 29

a substance that enters into and is altered in the course of a chemical reaction.

Question 30

shell

Answer 30

a hard rigid usually largely calcareous covering or support of an animal

Question 31

solute

Answer 31

a dissolved substance especially : a component of a solution present in smaller amount than the solvent.

Question 32

solution

Answer 32

homogeneous mixture of one or more solutes dissolved in a solvent.

Question 33

solvent

Answer 33

a usually liquid substance capable of dissolving or dispersing one or more other substances.

Question 34

subatomic particles

Answer 34

a particle which is smaller than an atom in size.

Question 35

valence electrons

Answer 35

a single electron or one of two or more electrons in the outer shell of an atom that is responsible for the chemical properties of the atom.