Exothermic and endothermic reactions

Question 1

When do chemical reactions occur?

Answer 1

when particles collide and are rearranged to form new particles

Question 2

Meaning of combustion?

Answer 2

the rearrangement of atoms causes energy to be released to their surroundings

Question 3

Formula of combustion

Answer 3

oxygen + fuel -(heat)> combustion

Question 4

What does energy result from?

Answer 4

• attractions between electrons and protons in atom
• repulsions between nuclei
• repulsions between electrons
• movement of electrons
• vibrations and rotations around bonds

Question 5

What are some examples of chemical energy?

Answer 5

coal, natural gas, wood, photosynthesis

Question 6

What does the law of conservation of energy say about energy

Answer 6

It cannot be created nor destroyed.
but it can change forms, when energy is transformed from one to another the total amount of energy remains the same

Question 7

Exothermic reaction meaning

Answer 7

a reaction that releases energy from the system in the form of heat

Question 8

Endothermic reaction meaning

Answer 8

A reaction that the system absorbs energy from its surrounding in the form of heat

Question 9

Products
/
/
Reactants/
this diagram represents which reaction?

Answer 9

endothermic

Question 10

Cellular respiration equation

Answer 10

glucose + oxygen -> carbon dioxide +water +energy