E and s end of 9 weeks test

group 1 of the periodic table

alkali metals

group 18 of the periodic table

noble gases

What does the period number represent

the amount of electron shells

what does the group number represent

the number of electrons in the valence electron shell

Mass of an atom includes

protons and neutrons

isotopes with different weights are different because of

neutrons

what doesn’t influence the mass of an atom

electrons

how does an atom become a cation

losing an electron

how does an atom become an anion

gaining an electron

what are ionic bonds

Bonds between a metal and a nonmetal

key properties of ionic compounds

high melting point, hard, brittle

what forms covalent bonds

nonmetals and metalloids

how does covalent bonds form

By sharing pairs of valence electrons

what makes a covalent bond polar

unequal sharing of electrons

what makes a covalent bond nonpolar

Equal sharing of electrons

what is acid

H+, 0-7 on the pH scale, turns litmus paper red

what is base

OH-, 7-14 on the pH scale, turns litmus paper blue

latitude measure

north and south

what is a map with quantitative data

a thematic map

What is a topographic map

map with contour lines and shows elevation

what is located 30 N to 60 N and vice versa south

temperate

What causes seasonal changes

earth’s tilted axis

where is the ozone

stratosphere

where is earth’s weather

troposphere

Where is the bad ozone

troposphere

where are the northern lights and international space station

thermosphere

percent of water

71%

how much freshwater

3%

what process leads to aquifers and groundwater formation

hydrolic cycle