8th grade semester 1 final- part 1

chemical equations

100

what type of equation is this

A + B --> AB

synthesis

200

what type of equation is this

AB --> A + B

decompostion

300

The terms on the left side of the equation are called 

reactants

400

balance this equation

H₂O  --> H₂ +  O₂

2(H₂O) --> 2(H₂) + O₂

500

balance this equation

C₆H₁₂O₆ + O₂ --> CO₂ + H₂O

C₆H₁₂O₆  + 6 (O₂ ) --> 6 (CO₂ ) + 6 (H₂O)

periodic chart

100

the number at the top of each box on the periodic chart for each element is called 

the atomic number

200

for each element on the periodic chart - the number of ________ is always the same as the number of ___________

protons , electrons

300

the bottom number of each box on the periodic chart for each element is called

the atomic mass or the mass number

400

to find the number of neutrons you need to 

subtract the atomic number from the atomic mass

OR. the bottom number minus the top number

500

the periodic chart is organized by type of atom- which type of atom has the most elements metals, non-metals, or noble gasses

metals

atoms and reactions

100

electrons have a __________ charge

negative

200

Protons have a __________ charge

positive

300

The electrons in the outer most ring of an atom are called the ____________________

valence electrons

400

the first ring of electrons can hold ______ electrons, the rest of the rings can hold _______ electrons

2,  8

500

Noble gasses are the most stable atoms because ______________

they have full electron rings

water chemistry

100

condensation is an _____________ reaction

(exothermic OR endothermic)

exothermic

200

give an example of an endothermic reaction

baking a cake, evaporation, many examples

300

in the water cycle- water evaporating from trees is called ________________

transpiration

400

the property of water that states water drops like to stick to other water drops is called

cohesion

500

Which type of water would a cargo ship float HIGHER in?

cold salty water OR warm fresh water

cold salty water

electricity

100

electrons that are not moving is called _______ electrcity

static

200

in a battery- the electrons move from the ________ to the _________

(fill in the blanks with the terms positive or negative)

in a battery- the electrons move from the  negative to the   positive

300

name 2 things that will conduct electricity

any kind of metal, water, salt water, acids

400

the universal rule in electricity (and chemistry) is 

_____________ attract

Opposites attract

500

circuit A: has a long wire, two light bulbs, and two batteries

circuit B: has a short wire, one light bulb, and two batteries.

Which circuit will have the fastest electrons and why?

circuit B-  it is the path of least resistance