Chemical Reactions

Question 1

In a chemical reaction the atoms or ions of one more substance, called ________, are rearranged, resulting in one or more different substances, called the _________

for example iron, water, and oxygen react to form hydrated iron oxide or rust.

Answer 1

reactants; products

Question 2

Matter is neither created or destroyed during a chemical reaction, so the mass of the products always _____ the mass of the reactant

Answer 2

equals, is the same

this is known as the law of conservation of mass.

Question 3

Chemical reactions can be represented by chemical equations Chemical equations show the reactants on the ____side and the products on the ____ side.

Answer 3

left; right

Question 4

because of the law of conservation of mass, a chemical equation must

Answer 4

be balanced

Question 5

the total number of atoms of an element on the left side must equal to the total number of atoms of the element on the ______

Answer 5

Right side

Question 6

2H2 + O2 → 2H2O, restated in words to explain how the reactants balance each other and are equal to the product

Answer 6

Restated in words: two molecules of hydrogen (H2 ) combine with one molecule of oxygen (O2 ) to form two molecules of water (H2O

Question 7

H₂O; which number or letter is the subscript and how do you know what the subscript is?

Answer 7

The subscript is the ₂; you will know which the subscript is by seeing the smaller font, on the bottom

Question 8

2H₂O; What is the coefficient ?

Answer 8

The large 2

Question 9

To balance a chemical equation, you can change the______—the number of units of any reactant or product. However, you cannot change the subscripts of any reactant or product.

Answer 9

Coefficient;

Question 10

Energy is involved in all chemical reactions. A reaction in which the reactants absorb energy from their surroundings is an _____reaction.

Answer 10

endothermic

Question 11

when you scramble an egg, you add heat energy and the egg solidifies. What type of chemical reaction is this?

Answer 11

Endothermic

Question 12

A reaction in which energy is given off with the products, usually in the form of heat or light, is an ________ reaction. When you burn wood in a fireplace, for example, heat and light energy are given off.

Answer 12

exothermic

Question 13

______energy is the amount of energy needed to get a reaction going

Answer 13

Activation

Question 14

Two basic types of Enegry

Answer 14

Potential and kinetic

Question 15

An object will have _____ energy because of its position

Answer 15

Potential

Question 16

An object will have _____ energy because it moves

Answer 16

Kinetic

Question 17

When you raise a hammer it has what type of energy(at its peak height)

Answer 17

Potential

Question 18

When you swing the hammer it has what type of energy

Answer 18

Kinetic

Question 19

Once the hammer hits the nail, it ______ energy to the new

Answer 19

Transfers

Question 20

The energy transferred to the nail is equal to the power that the hammer was swung; the unit of measurement that we use to determine the amount of energy that was transferred is called

Answer 20

Joules

Question 21

The rate of doing work or consuming energy is called power; this can be measured in the unit

Answer 21

Horse power

Question 22

An ion is what in relation to an atom

Answer 22

It is an electrically charged at once the Adam loses or gains a charge

Question 23

Physicist Albert Einstein discovered the relationship between energy and mass and expressed it in the equation E = mc 2

Question 24

E = mc 2 ; what does E, represent

Answer 24

Enegry

Question 25

E = mc 2 ; what does M and C represent

Answer 25

Mass and the speed of light