chemistry Flashcards
What is chemistry?
Chemistry is the study of matter.
5 points of particle theory:
- All matter is made up of particles
- Particles never stop moving
- There is space between particles
- When heated, particles move faster
- Particles are attracted to each other.
What is mass and how is it measured?
Mass is how many particles there are, and can be measured in grams (g) on a scale.
How do you measure the volume of a regular shape?
Regular shape = LXWXH
How do you measure the volume of an irregular shape?
You use water displacement.
What are the 6 changes of state?
Melting, Freezing, Condensation, Evaporation, Deposition, Sublimation
What is deposition?
Solid to gas
What is sublimation?
Gas to solid
What are quantitative observations?
Quantitative observations are observations in numbers
What are qualitative observations?
Qualitative observations are observations in non-numeric form, using your 5 senses.
What are physical properties?
Describes physical characteristics of a substance
What are chemical properties?
Describes how an object reacts ex. burning, rusting
What does heterogeneous mean?
Heterogeneous means that the mixture is not uniform. Mechanical Mixtures are heterogeneous.
What does homogenous mean?
Homogenous means that the mixture is uniform. Solutions are homogenous.
What are mixtures?
Mixtures have 2 or more types of particles.
What are pure substances?
Pure substances have only one type of particle
What is a physical change?
When matter changes and no new substance is made
What is a chemical change?
A chemical change is when a new substance is made
What are the 5 pieces of evidence of a chemical change?
- A new substance is formed.
- The change is irreversible
- Gas is made
- Heat and light is produced
- Colour change
What is the formula for density?
D = M/V
What is density?
Density is a measure of how closely packed particles are
What are elements?
Pure substances composed of only one type of particle
How many known elements are there, and how many occur naturally?
There are 118 elements, with 92 naturally occurring.