What happens when chemical bonds break and new bonds form?
a. a Physical change
b. a chemical reaction
c. matter is destroyed
d. surface area increases
What is b. a chemical reaction?
100
The minimum amount of energy needed to start a reaction.
What is activation energy?
100
The number placed below an element's symbol in a chemical formula is called a _____.
What is a subscript?
100
What is the best form of fire safety?
What is fire prevention?
200
Anything that has mass and takes up space.
What is matter?
200
What type of reaction is FeS + 2 HCl ---------FeCl2 + H2S?
DOUBLE POINTS!
What is a double replacement?
200
A material used to DECREASE the rate of a chemical reaction.
What is an inhibitor?
200
The number placed in front of an element's symbol in a chemical formula is called a ___________.
What is a coefficient?
200
The best way to put out a small kitchen fire is:
What is to cover it or use a home fire extinguisher?
300
CaCO3 represents a _________ _________.
What is a chemical formula?
300
The only sure evidence for a chemical reaction.
What is the production of one of more new substances?
300
Which of the following does NOT increase the number of particles of a substance availalbe to react in a chemical reaction?
A. increasing the concentration.
B. increasing the surface area.
C. adding a catalyst.
D. increasing the mass.
What is C adding a catalyst?
300
In a chemical equation, numbers often appear in front of a chemical formula. These numbers tell you the number of what ?
What is the number of molecules or atoms of each substance in the reaction?
300
The principle of conservation of mass states this.
What is mass cannot be created nor destroyed?
400
A chemical equation that shows the same number of each kind of atom on both sides of the equation is said to be _________________.
What is balanced?
400
A shorter easier way to show a chemical reactions, using symbols instead of words is called?
What is chemical equation?
400
Chemicals that act as biological catalysts by speeding up reactions in living things are this.
What are enzymes?
400
Identify the products in this equation:
H2O ------- H2 + O2
What is H2 and O2?
400
Removing oxygen from a fire will do this.
DOUBLE POINTS!!!
What is bring the fire under control?
500
Which on is balanced?
A. H202-------H2O + O2
B. 2 Fe2O3 + 3C --------4 Fe + 3 CO2
C.SO2 +O2 + 2 H2O --------4 H2SO4
What is B? B. 2 Fe2O3 + 3C --------4 Fe + 3 CO2
500
A chemical reaction that absorbs energy in the form of heat is described as this.
What is endothermic?
500
A rapid reaction between oxygen and a fuel is known as this.
DOUBLE POINTS!
What is combustion?
500
Identify the reactants in this equation:
Na + Cl2 --------NaCl2
What is NaCl2?
500
The difference between chemical reactions in an open and closed system.
What is in an open system, matter can enter from or escape to the surroundings and in a closed system matter is not allowed to enter from or escape to the surroundings?