ChemCom Unit 1A
A pure substance made of only one type of atom
Element is a pure substance made of only one type of atom
A substance that can be decomposed into simpler substances
A compound is a substance that can be decomposed into simpler substances
What kind of mixture is an alloy?
An alloy is a homogenous mixture of metals.
What kind of change is heating iron to its melting point?
Heating a sample to its melting point is a physical change.
How would one classify a solution of salt in water?
A solution of salt in water would be classified as a homogenous mixture.
Can a mixture be separated by physical or chemical means?
A mixture can be separated by physical means.
What 2 terms come under the heading of 'substance' in the study of matter?
Elements and compounds come under the heading ' substance.'
What is the ability of a person to get nearly the same result each time they make a measurement?
What is the formula for calculating percent error?
What has its components present in a fixed ratio? (Follows Law of Definite Proportions)
A compound has its components present in a fixed ratio
What type of observation is a numeric measurement, Qualitative or Quantitative
A measurement is a quantitative observation
What are significant digits?
Significant digits include all the known digits on an instrument plus one estimated digit.
Express the formula for density in a sentence.
The formula for density is mass divided by the volume of a substance.
How much does 25.0 ml of water weigh?
25.0 ml H
O has a mass of 25.0 g (water's density is 1.0 g/ml)
Name the 7 elements that exist as diatomic molecules in nature.
Hydrogen, nitrogen, oxygen, fluorine, chlorine, bromine, & iodine
What state of matter has the greatest forces of attraction between its particles?
A solid has the greatest forces of attraction between its particles
What type of matter has 2 or more substances in
no fixed ratio
A mixture has 2 or more substances in no fixed ratio.
Dissolving cupric chloride in water is an example of a (chemical , physical ) change.
Dissolving cupric chloride in water is an example of a PHYSICAL change.
What state of matter would occupy the entire volume of a container?
A gas occupies the entire volume of a container.
What symbol is used to indicate a substance is dissolved in water? What word is this the abbreviation?
(aq) which is aqueous
Which state of matter has no definite shape but has a definite volume?
What do we call the substances a chemical equation starts with?
The term "Matter" can be broken into 2 categories of which one is pure and the other is not. What are these two categories?
Substances and Mixtures
What are the two types of mixtures?
Homogenous and Heterogenous
What type of mixture has substances uniformly distributed and the particles too small to be seen?
ChemCom Unit 1A
Chemistry in the Community Unit 1A review