Chapters 4-5

Question 1

element symbols

Answer 1

a set of abbreviations for the chemical elements

Question 2

law of constant composition

Answer 2

a compound always has the same composition, regardless of where it comes from

Question 3

Dalton’s atomic theory (pg. 80)

Answer 3

1. Elements are made of tiny particles called atoms
2. All atoms of a given element are identical
3. The atoms of a given element are different from those of any other atoms
4. Atoms of one element can combine with atoms of other elements to form compounds. A given compound always has the same relative numbers and types of atoms.
5. Atoms are indivisible in chemical processes. That is, atoms are not created or destroyed in chemical reactions. A chemical reaction simply chances the way atoms are grouped together.

Question 4

atoms

Answer 4

the fundamental unit of which elements are composed

Question 5

compound

Answer 5

a distinct supstance that is composed of the atoms of two ore more elements and always contains exactly the same relative mass of those elements

Question 6

chemical formula

Answer 6

the types pf atoms and the number of each type in each unit (molecule) of a given compound

Question 7

electrons

Answer 7

a negatively charged particle that occupies the space around the nucleues of an atom

Question 8

nuclear atom

Answer 8

an atom with a dense center of positive charge

Question 9

nucleus

Answer 9

The positively charged central core of an atom, containing most of its mass.

Question 10

proton

Answer 10

a positively charged particle in an atomic nucleus

Question 11

neutron

Answer 11

a particle in the atomic nucleus with a mass aproximately equal to a neutron but with no charge

Question 12

isotopes

Answer 12

atoms with the same number of protons but different number of neutrons

Question 13

atomic number

Answer 13

the number of protons in a nucleus

Question 14

mass number

Answer 14

the sum of the number of neutrons and the number of protons in a given nucleus

Question 15

periodic table

Answer 15

a chart that shows all the known elements and gives a good deal of information about each

Question 16

groups

Answer 16

a family of elements that lie in the same vertical column on the periodic table

Question 17

alkali metals

Answer 17

the first column of elements

Question 18

alkaline earth metals

Answer 18

the group 2 elements

Question 19

halogens

Answer 19

group 7 elements

Question 20

noble gases

Answer 20

group 8 elements

Question 21

transition metals

Answer 21

several series of elements in which inner orbitals are being filled

Question 22

metals

Answer 22

1. efficient conductor of heat and electricity
2. malleability (hammered into thin sheets)
3. ductility (pulled into wires)
4. a lustrous (shiny) appearance

Question 23

nonmetals

Answer 23

upper right of periodic table, an element that does not exhibit metallic characteristics. Chemically, a typical nometal accpets electrons from a metal

Question 24

metalliods/semimetals

Answer 24

The elements that lie close to the “stair step.” Often show a mixture of metallic and nonmetallic properities. Ex: silicon, germanium, arsenic, antimony, tellurium

Question 25

diatomic molecules

Answer 25

molecules made up of two atoms

Question 26

allotropes

Answer 26

different forms of a given element

Question 27

ion

Answer 27

an atom or a group of itoms that has a net positive or negative charge

Question 28

cation

Answer 28

a positive ion

Question 29

anion

Answer 29

a negatively charged ion

Question 30

ionic compounds

Answer 30

a coumpound that results when a metal reacts with a nonmetal to form actions and anions