SOL science prep 8th grade Flashcards
the total amount of matter in an object
mass
can occur at surface of liquid without heating (eventually a cup of water will evaporate if left unattended
Evaporation
change from solid to gas
Sublimation
matter that is composed of one type of atom
element
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model which shows electrons traveling in specific energy levels around a nucleus, electrons closest to nucleus have low energy, electrons farther away have high energy
Electronic Cloud
an atom of an element that has a different number of Neutrons
Isotopes
uses the element symbol and dots to repersent outer energy level electrons
Electron Dot Diagram
Where are metals on the periodic table?
left side
malleable and ductile
metals
what does malleable mean?
can be hammered into sheets (think: malleable=mallet)
what does ductile mean?
drawn/made into wires
do metals or metalloids or non-metals have few electrons on the outer level (valence electrons)
metals
all but mercury are solid at room temperature
metals
where are non-metals on the periodic table?
right side
more than half are gasses at room temperature
not meteable
not ductile
non-metals
where are metalloids on the periodic table?
found along or touching the staircase
have properties of both metals and non-metals
have about a half complete set of valence electrons
metalloids
as elements go from left to right they get less reactive
1-7 of them
go from left to right
follow a repeating pattern
rows (periods)
similar chemical and physical properties
1-18
ones is same section have same number of valence electrons
columns (groups)
what groups are highly reactive
1, 2, 17
what group is Alkali Metals
1
what group is Alkaline Earth Metals
2
what group is the Halogens
17
what group is the Noble Gasses and are unreactive because outer energy level is full
18
what groups are transition metals. often occur in nature uncombined
3-12
substance made of the combined atoms of 2 or more elements
compound
two or more atoms combine to form a new substance that has new properties (physical or chemical) than the original elements
Chemical Bonding
tells what elements a compound contains and the number of atoms
Chemical Formula
when 2 or more Ions conbine to form neutrally charged compound
Ionic Bonding
the need to have a full outer ring or energy level
octet rule
an atom that has gained or lost electrons to have a full outer ring (now will be happy
Ion
charge an atom gets after gaining or losing electrons
Oxidation
when 2 or more atoms share valence electrons
electrons are shared
occurs between 2 nonmetals
nonmetals do not give up electrons
Covalent Bonding
substance that produces hydrogen ions (H+) in solution
Acid
what are the four properties of acids?
taste sour
are electrolytes (can conduct electricity)
corrosive
indicators to produce a predictable color change (red)
substance that produces hydroxide ions (OH) in solution also accepts H+ from acids
base
what are the 5 properties of bases?
in undissolved states, many are crystalline solid (feels slippery)
bitter taste
strong bases are corrosive
react with indicators (blue)
compound formed when negative ions of an acid combine with positive ions from a base
salt