Chapter 1/Chapter 2 Flashcards
(45 cards)
How is chemistry studied? (4 ways)
Macroscopic World
Microscopic World
quantitative
qualitative
What is an atom?
submicroscopic particles that constitute the fundamental building blocks of matter.
What are molecules?
geometrical arrangements of atoms
What is chemistry?
the study of matter and the changes it undergoes
What are the steps to the scientific method? (5)
observations
research
hypothesis
experiments
theory
What is a scientific law?
brief statement that summarizes pas t observations and predicts future ones
law of conservation of mass
matter is neither created nor destroyed
What is matter? what are two different ways to classify matter?
anything that takes up space and has mass
by state and by composition
What is a pure substance? What are some examples?
Pure substance is made up of only one component and its composition does not vary.
helium, water, table salt, ice
What is a mixture? What is an example.
A mixture is composed of two or more components that varies from one sample to another.
sweetened tea- the amount of sugar depends on the person. there is no set amount
gasoline
What are two types of pure substances?
Elements and compounds
What is an element?
substance that cannot be chemically broken down
What is a compound? Example?
substance composed of two or more elements in a fixed, definite proportion
water
What are two types of mixtures?
heterogeneous and homogeneous
heterogeneous? Give an example.
composition varies from one region of the mixture to another
wet sand
homogeneous? Give an example.
same composition throughout
sweetened tea
What are four ways to separate mixtures?
decanting
distillation
volatile
filtration
What happens in decanting?
Give an example.
separating the two composition by pouring one into another container
one can separate a mixture of sand and water by pouring water into another container
What happens in distillation? Is this used for homogeneous mixtures of heterogeneous mixtures?
a process in which the mixture is heated to boil off the more easily vaporizable liquid
homogeneous
what is volatile?
a liquid that can vaporizes easily
What happens in filtration?
mixture is poured through filter paper in a funnel.
What is a physical change? example?
change from one state to another. the composition does not change.
sugar dissolving color gas at room temp odor boiling point
what is a chemical change? example?
changes that alter the composition of matter
rusting iron
dry ice subliming
decomposing
very reactive
what is energy?
capacity to do work