Unit #1 Study Guide: Lab Safety, Introduction to science, and matter.
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Lab Safety
 You should wear safety goggles if you are working with a heat source,
working with chemicals, or working with anything that might get into your
eyes.
 To see if a piece of glassware is hot you should place the back of your hand
near it.
Introduction to Science
 Technology can best be defined as applied science.
 Pure science is best defined as the continuing search for new knowledge.
 Scientific theories can be changed or replaced when new discoveries are
made.
 Weight is the force with which gravity pulls on a quantity of matter.
 The unit used to measure the height in science is the meter.
 The unit is used to measure mass in science is the kilogram.
 The SI units for measuring temperature are Celsius or kelvin.
 A line graph is used to show a change in data over time.
 A bar graph is used to show a comparison of several items or events.
 A pie chart is used to show data that are parts of a whole.
 The main branches of natural science are life, physical and Earth science.
 A scientific law is a description of a natural event.
 Scientists test a hypothesis by doing experiments.
 The two main branches of science are natural and social science.
 A scientific theory is an explanation that has been tested by many
observations.
 A scientific model is a representation of a real event or object.
Matter
 A molecule of water (H2O) is made from chemically combining two
hydrogen atoms and one oxygen atom.
 A pure substance is a material that can be represented by a chemical
formula. (Compounds & elements)
 The chemical formula for water, H2O, means that each water molecule
contains two hydrogen atoms and one oxygen atom.
 The production or release of gas, and the change of color are all potential
signs of chemical change.
 Evaporation is a physical change not a chemical change.
 An Atom is the smallest unit of an element that maintains the properties of
that element.
 Solids, liquids, and gases are three forms of matter, they all have mass, take
up space and are made of atoms.
 There are 5 atoms in a single molecule of Fe2O3? (2 +3 = 5 Atoms)
The chemical symbol for sulfuric acid is H2SO4. It has 7 atoms. (2+1+4=7
atoms)
 Elements, compounds, and molecules are all pure substances, mixtures are
not.
 A molecule is group of atoms that acts as a unit.
 Chemical properties include: reactivity, flammability, nonflammability
 Physical properties include: melting point, density, color, freezing point,
boiling point, solubility.
 An object’s volume can be found by dividing its mass by its volume. d= m/v
 Size, shape and position can all be affected by a physical changes.
 The different substances in a mixture keep their properties.
 Signs of chemical change include change in color, fizzing, burning and
changes in color.
 Boiling, evaporation, freezing, melting, moving, shattering, dissolving,
bending and condensing are all physical changes.
 A chemical change can only be reversed by a chemical change. Not a
physical change.
 A chemical change occurs whenever a new substance is formed.
 Matter is defined as anything that has mass and takes up space.
 The smallest unit of a substance that behaves like the substance is a
molecule.
 A compound is made of at least two different types of atoms?
 A pure substance has a fixed composition, a mixture does not.
 Examples of a chemical changes include: paint fading, and food being
digested.
 An element is a substance that cannot be broken down into simpler
substances.
 The chemical formula for table sugar is C12H22O11. It contains 12 Carbon
atoms (C), 22 Hydrogen atoms, and 11 Oxygen atoms (O). (12+22+11= 42
atoms)
 Knowing the chemical properties of a substance will tell you how the
substance reacts with other substances.