Chemical Reactions
Atoms and Molecules
Physical Changes
Law of Conservation of matter
Random
100
What is a chemical reaction
When molecules break apart and recombine with something new
100
What is an atom?
Building block of everything, smallest part of matter
100
What is a physical reaction?
Atoms and molecules change but don't break apart
100
What is matter?
Anything that takes up space and has mass
100
What part of atoms have positive charge?
Protons
200
Here is a chemical reaction - explain what happens to the carbon
CH4+ 2O2 -> CO2 + 2H2O
Carbon breaks off from CH4 and combines with O2 to create CO2
200
What is a molecule?
Combination of atoms
200
What is an example of a physical change?
Water Melting
Water Boiling
200
What is law of conservation of matter?
matter cannot be created or destroyed
200
What part of atoms have negative charge
Electrons
300
A gate made of painted iron is beginning to rust in areas where the paint has worn away. The paint served as a protective barrier between the iron and the oxygen in the air. Why is the formation of rust considered a chemical process?
a. Rust is a different color than iron.
b. Rust has the same arrangement and types of atoms as pure iron.
c. Rust is just a different state of matter than iron.
d. Rust and iron are completely different substances with different properties.
D. Rust and iron are completely different substances with different properties.
300
How many TOTAL atoms are in the following molecule(They can be the same atom) ?
C6H12O6 - Glucose
C6H12O6 - Glucose
Carbon - 6
Hydrogen 12
Oxygen 6
Total: 24
300
How do you know something undergoes a physical change?
Changes color
change in size/shape
no change in chemicals
300
Here is a chemical reaction - what happens to the hydrogen and where does it go?
Zn + 2HCl → ZnCl2 + H2
Hydrogen separates from Chlorine and stays by itself to create H2 . The Zinc and Chlorine combine to make ZnCl2
300
What is difference between conduction and convection?
Conduction - transfer of heat through contact
Convection - transfer of heat through liquid or gas
400
What is the difference between a chemical and phyiscal change?
Chemical changes - atoms break away from molecules
Physical changes - atoms and molecules just move faster or slower
400
What happens to molecules during a chemical reaction
The atoms break off the molecule and recombine with other atoms to form a new substance
400
Is photosynthesis a chemical or physical change?
6CO2 + 6H2O + light -> C6H12O6 (sugar) + 6O2
Chemical
400
Why can't matter be created or destroyed?
It is always cycled and transfered through to a different type
400
What is an exothermic reaction?
Heat exits and makes surroundings warmer
500
The drawings represent the molecules in a sample of matter that underwent a change in state.
Based on the drawings, is this a chemical or physical change and how do you know?
Physical - they are just moving faster and not breaking apart
500
What three things are all atoms made of?
Protons, Neutrons, Electrons
500
H2O→ H2O
2H2+ O2 -> 2H2O
Which one is a physical change and how do you know?
H2O→ H2O
Doesn't change form
500
Here is photosynthesis - What is the purpose of light.
6CO2 + 6H2O + light -> C6H12O6 (sugar) + 6O2
Energy source
500
Flourine has an atomic number of 9, and an atomic mass of 19
How many protons, neutrons and electrons does it have?
Protons - 9
neutrons - 10
Electrons -9