Lab Safety and Atoms
Name two ways to stay safe in a chemistry lab?
Pony tail, close-toed shoes, goggles, no food/drink
Is a melted popsicle an example of a physical change?
What is YES? You can melt and refreeze a popsicle and it will still be a popsicle.
Name an example of a physical change.
Cutting log, crumble paper, break pencil
Acid
What is the scientific name of water?
H2O
Ice + Heat = ?
Melting or liquid
Name an example of a chemical change
burning a paper
What pH is water?
Neutral or 7
Protons are _______(positive, negative or neutral?)
Positive
What can you do to change water into a gas?
Add heat
We blew up a balloon with baking soda and vinegar. Was this an example of a physical or chemical change? Explain
Physical - balloon got bigger
Chemical - vinegar and baking soda go boom
These molecules are very close together and do not move much.
Solid
pH is on a scale from 0 to what?
14
Proton, Neutron, Electron
What could I do to water to put it through a physical change?
Heat, Freeze
Name a food that is an example of a chemical change and explain why.
What is a cake, because you cannot turn a cake back into the eggs, flour, sugar, etc. that you mixed together?
Oobleck is an example of which states and why?
When untouched, acts as water - flows
When squeezed or held, acts as solid - holds its shape
Name one way people use pH in real life.
Testing pH of pools, farmers testing pH of soil, pH of water ecosystems
Electrons are _________ (positive, negative or neutral?)
Negative!
Explain how the water cycle an example of a physical change.
it is a physical change, because water changes from a liquid/solid when it precipitates, to a gas when it evaporates, then forms back into a liquid when it condensates. Then the process repeats again with the same substance, WATER!
True or False. Making pancakes is a physical change
False! You cook the batter and it turns into a new substance.
These molecules are spread far apart and move freely wherever there is open space.
GAS
What pH is lemon juice?
About 2