genchem Flashcards
(24 cards)
What is a Pure Substance?
Matter that has only 1 set of chemical and physical properties.
Pure water always has the exact same chemical and physical properties under the same conditions.
What is a Mixture?
Two or more pure substances mixed together, which can always be separated by physical means.
Unlike pure substances.
Define Heterogeneous Mixture.
A mixture with an uneven distribution of substances, where parts can be seen.
Examples include sand, granite, wood, milk, and blood.
Define Homogeneous Mixture.
A mixture where components are evenly mixed and cannot be seen separately.
More pure examples include seawater and distillation plants.
What are the two categories of Pure Substances?
- Compounds
- Elements
What is a Compound?
Two or more elements chemically bonded together, having only one set of properties and cannot be separated by physical processes.
Only separable by chemical reaction.
What is an Element?
Substances made up of only one type of atom that cannot be separated by any physical or chemical processes.
Examples include gold, carbon, and helium.
Define Heat.
The amount of energy transferred from one body to another due to a temperature difference.
What is Temperature?
A measure of the average kinetic energy of the molecules of a substance.
Fill in the blank: Celsius to Fahrenheit conversion formula is F = _______.
9/5 C + 32
Fill in the blank: Fahrenheit to Celsius conversion formula is C = _______.
5/9 x (F - 32)
Fill in the blank: Celsius to Kelvin conversion formula is K = _______.
C + 273.15
What does a measurement involve?
NUMBER and UNIT
What is the SI unit for Mass?
Kilogram (kg)
1 kg = 1000 g
What is the SI unit for Length?
Meter (m)
Longer distances use kilometers (1 km = 1000 m) and shorter distances use centimeters (1 m = 100 cm).
What is Volume?
The amount of space an object occupies, a derived unit from base units.
Define Density.
The amount of mass of an object divided by its volume.
What are Significant Figures?
If a decimal point is present, start on the P side and count non-zero digits to the end. If absent, start on the A side.
What unit measures temperature?
Degrees (°)
What is the freezing point of water?
0°C
What is the boiling point of water?
100°C
True or False: Lightning can reach temperatures up to 30,000 °C.
True
What is the approximate temperature at the middle of the sun?
15 million degrees Celsius.
What was the coldest temperature recorded in Wales?
-22°C in 1987.
