Unit Two Test Flashcards
(41 cards)
Mixtures?
Separated by chemical means. Homogenous or heterogeneous. Not pure. Made if at least two different substances.
Compounds?
Compounds: separated with physical touch. Made of two or more elements Either stable it unstable. Highly reactive it less reactive. Pure
Compounds and mixtures both…?
Are made of atoms.
What is the composition of the atmosphere ?
Nitrogen, oxygen, and other gases.
The atmossphere is classified as a…
Mixture
Compound examples
Water, plastic, rubbing alcohol, natural gas.
Mixture examples
Air, trail mix, tea, coffee, dirt
When is a change of chemical or physical?
When the temperature changes
What is a precipitate and what does it indicate?
It is a solid formed by a chemical reaction.-A precipitate forms when the product of a chemical reaction is insoluble in the solvent being used.
Chemical change?
Always causes a new substance to be formed with new properties. A firm of light, heat, odor, cold, electricity? Bubbles, sound.
List examples of chemical change?
Baking soda and vinegar together–bubbles . A rotten egg– odor. Fire–describe it — hot light bright produces smoke when you burn anything it indicates a chemical change.
Solid!
When the water molecules are tightly packed together
Liquid!
When the water molecules overlap and slide together
Gas!
When the water molecules are far apart as can be.
Temperature??
Is energy: temperature is what changes the physical state of matter.
Physical change?
Particle motion determines the state of a substance. All parties are in motion.
A particle is…
A single unit of matter. It can be a single atom or the single molecule of a compound.
Atomosphere is….
Composed of 79% nitrogen(element). 19% oxygen. And the remaining is 1% of other gases including co2– too much can suffocate us.
When does the change of state of matter occur
When the temperature changes
What are the clues of chemical change?
Heat, light, sound, blubbling, electricity, heat, odor, cold
Best evidence of chemical change?
Mixing vinegar and baking soda– bubbling
Relate particle motion to state change.
Gas– the particles move around fastest and with space in between. Liquid–the particles slid past one another overlapping and such.
Solid– the particles are closely packed and vibrate a little
How does temperature affect particle motion
It causes them to move faster as they have more energy
How does temperature affect state change
An increase in temperature causes particles to start moving around. If you heat something long enough and high enough, it will eventually turn into a gas (after going through the liquid stage first). When things get cold, particles slow down, eventually causing things to be in a solid state.
