science test reactions

Question 1

What is the most important chemical reaction on earth

Answer 1

photosynthesis

Question 2

What are the reactants in photosynthesis

Answer 2

water and carbon dioxide

Question 3

What are the products of photosynthesis

Answer 3

glucose and oxygen

Question 4

Why is photosynthesis so important

Answer 4

it produces glucose and makes breathable air for humans

Question 5

Where does the largest percentage of photosynthesis take place on the earth

Answer 5

the ocean

Question 6

What is the energy source for photosynthesis?

Answer 6

light energy from the sun

Question 7

A reaction that requires energy to take place is called

Answer 7

endogenic energy

Question 8

balanced equation for photosynthesis

Answer 8

6CO2 + 6H2O -> C6H12O6 + 6O2

Question 9

What is the opposite reaction of photosynthesis called

Answer 9

cellular respiration

Question 10

Why do organisms use cellular respiration

Answer 10

to generate energy

Question 11

A reaction that gives off energy is called

Answer 11

exergonic reaction

Question 12

The cell energy product of cellular respiration is called

Answer 12

ATP

Question 13

How is combustion similar to cellular respiration

Answer 13

They both release energy and produce carbon dioxide and water

Question 14

Why is too much combustion a problem on the earth

Answer 14

bec it blocks heat coming out of earth

Question 15

Give 4 alternatives to using combustion as an energy source

Answer 15

Solar power, water energy, biofuels, and wind energy

Question 16

Why is ozone important

Answer 16

It absorbs some radiation from the sun which protects the earth’s surface. Protects us from the ultraviolet rays

Question 17

In what layer of the atmosphere is the ozone layer located

Answer 17

stratosphere

Question 18

2 reactions that make ozone

Answer 18

O2 -> O + O
O + O2 -> O3

Question 19

What is the energy source that makes the first reaction take place

Answer 19

ultra violet radiation

Question 20

What type of chemical reaction is the first reaction

Answer 20

decomposition

Question 21

What type of chemical reaction is the second reaction

Answer 21

synthesis

Question 22

determine if something is an element, compound, or mixture

Answer 22

Element cannot be broken down, compound can be broken down by chemical reactions, mixture can be broken down by physical reactions

Question 23

parts of a chemical equation

Answer 23

reactants yield products

Question 24

the law of constant proportions is and how it relates to chemical formulas and chemical reactions

Answer 24

law of constant proportions – the numbers in a compound formula cannot be changed, ratios are constant

Question 25

how was the law of constant proportions was shown in the decomposition of water lab and zinc in hydrochloric acid lab

Answer 25

2 hydrogens to one oxygen and the ratio stays the same

Question 26

when a reaction uses up one of the reactants the reaction stops and relate this to the zinc in hydrochloric acid lab

Answer 26

Limiting reactant, runs out of one of two reactants, ran out of hydrochloric acid

Question 27

how chemical reactions differ from physical reactions

Answer 27

bigger changes, minor changes, new substance, no new substance, heat change, minor heat change,