States and Types
This type of matter has a fixed shape and fixed volume; its particles vibrate in place.
What is a solid?
The amount of matter in an object; it does not change with location.
What is mass?
A change where the form of matter changes but the substance stays the same (e.g., melting ice).
What is a physical change?
Substances that taste sour, react with metals, and have pH less than 7.
What are acids?
The tiny particle that makes up all matter; the basic unit of an element.
What is an atom?
A substance made of only one kind of atom that cannot be broken down by chemical means.
What is an element?
The amount of space an object occupies; measured in liters or cubic centimeters.
What is volume?
The process where a liquid becomes a gas at the surface at temperatures below the boiling point.
What is evaporation?
Substances that feel slippery, taste bitter, and have pH greater than 7.
What are bases?
The model/theory used to explain how the motion of particles relates to temperature and state of matter.
What is the kinetic molecular theory?
A homogeneous substance composed of two or more elements chemically combined in fixed ratios.
What is a compound?
Mass divided by volume; this property helps identify a substance and whether it floats or sinks.
What is density?
A chemical change indicator that shows new substances formed, such as production of gas, color change, or temperature change.
What is evidence of a chemical change (e.g., gas evolution, temperature change)?
A universal indicator color or pH value typical for a neutral substance (pure water).
What is pH 7 or neutral (pure water)?
In the kinetic molecular theory, increasing temperature does what to the average kinetic energy of particles?
What is it increases (or increases the average kinetic energy)?
This mixture has visibly different parts and can often be separated by physical means (e.g., salad).
What is a heterogeneous mixture?
A physical property describing how easily a material can be stretched into wire.
What is ductility?
The specific temperature at which a solid turns into a liquid.
What is the melting point?
A strong acid commonly used in laboratories (formula).
What is hydrochloric acid (HCl)?
The type of bonding typically found between metal atoms allowing them to conduct electricity and be malleable/ductile.
What is metallic bonding?
At very high energy, matter becomes ionized and often conducts electricity; it’s found in stars.
What is plasma?
The amount of hydrogen-ion concentration measured on a scale from 0 to 14; indicates acidity or basicity.
What is pH?
The reverse of condensation; when a gas becomes a liquid (often releases energy).
What is evaporation?
The scale is logarithmic. If solution A has pH 3 and solution B has pH 5, solution A has how many times greater [H+] concentration than B?
What is 100 times greater? (Because pH difference of 2 means 10^2 = 100 times greater [H+].)
When two or more atoms share electrons to form molecules, this bond is called what?
What is a covalent bond?