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Study Guide for Grade 7 Science Midterm
1. Draw a series circuit
.
2. Draw a parallel circuit.
2. In a series circuit, if one bulb went out, what would happen to the others?
They would go out Why: The circuit is broken, no electricity flowing
4.. In a parallel circuit, if one bulb went out, what would happen to the others?
They would stay lit Why there is an alternate path for electrons to flow
5. What is the purpose of a 3 prong plug? grounds the electricity and is a safety
feature
6. Where is the strongest part of a bar magnet? At poles
7. Like poles…repel
8. Unlike poles … attract
9. Like charges…repel
10. Unlike charges … attract
11.. Which 3 metals are attracted to a magnet iron, nickel, cobalt
12. Name 2 ways to increase the strength of an electromagnet: stronger battery (voltage
source) more coils
13. What is a magnetic field The invisible force around a magnet
14. Iron is considered to be a ferromagnetic material because it is attracted to a magnet
15.Describe an electromagnet: a solenoid with a ferromagnetic core and electricity
source. A magnet that can be turned on and off
16. The flow of electrons in a continuous path is called an electric an electric circuit
17. If you break a magnet, you get 2 smaller magnets each with a north and south pole
T
18. A battery is a voltage source.
19. Name 3 subatomic particles which make up an atom: protons, neutrons, electrons
20.All matter is made of atoms
21. The buildup of charge is called static electricity
22. The mass of an atom is located in the nucleus this is also the middle of the atom.
23. What is a pure substance? A substance made of only one kind of matter and having
definite properties
Examples of pure substances: compounds and elements
24. What is a physical property? A property that describes a substance; but the
substance does not change atomic make up:
Examples of Physical properties: phase change, conductivity, color, texture
25. What is a chemical property? A property that describes a substance’s ability to
change atomic make up:
26. Examples of chemical properties: flammability, ability to rust, ability to tarnish
Define AND GIVE EXAMPLE
Mass: how much matter in a substance
Volume: the amount of space, matter occupies
Density: the amount of mass per volume of a substance
Atom: smallest unit of matter
Matter: anything that has mass and volume
Proton: a positively charged particle
Neutron: (Know how to find the number of neutrons) a neutral particel
Electron: a negatively charged particle
Atomic number: KNOW HOW TO FIND ON PERIODIC TABLE
Atomic Mass: KNOW HOW TO FIND ON PERIODIC TABLE : see above
Element: a substance that cannot be broken down into other substance by chemical or
physical means: made of only one kind of atom.
Compound: 2 OR MORE ELEMENTS CHEMICALLY BOUND IN A FIXED RATIO
Chemical symbol: THE LETTERS REPRESENTING AN ELEMENT. Au- GOLD
Semiconductor: A SUBSTANCE THAT CAN CONDUCT ELECTRICITY UNDER
CERTAIN CONDITIONS-Si
Chemical Formula: THE LETTERS AND NUMBERS THAT REPRESENT A CHEMICAL
COMPOUND C6H12O6
Chemical reaction: Any reaction that results in a new substance
Solution: a homogeneous mixture containing a solvent and at least 1 solute. Can be
separated through evaporation of solvent.
Mixture: 2 or more substances physically together, can be separated
Homogeneous mixture: a mixture that is mixed so well you cannot see the separate
parts. Also called a solution
Heterogeneous mixture: a mixture that you can see the separate parts, can be
separated through filtering or settling. Also called a suspension
Physical change: a change which does not alter the substances atomic structure
Chemical change: a change which alters the atomic structure of a substance, resulting
in a new substance with different properties.
Solid: (Give 3 properties as well) a substance with definite shape and definite volume.
No compressibility: particles close, vibrate in place
Liquid: (Give 3 properties as well) a substance with definite volume and indefinite
shape. Can flow. Can be compressed. Liquids such as water can exhibit surface
tension. Particles little movement but can slide past eachother
Gas: (Give 3 properties as well) indefinite shape indefinite volume. Can flow. Can be
compressed: particles move very fast and are far apart
Viscosity: resistance to flowing: high viscosity: syrup low viscosity: juice
1. Phase change: KNOW HOW TO READ A PHASE CHANGE GRAPH
Vaporization liquid to gas
Sublimation solid to gas
Evaporation: liquid to gas only at surface
Boiling: liquid to gas all the way through substance
Condensation gas to liquid
Melting solid to liquid
Freezing liquid to solid
Fluid ability to flow
Melting Point: temperature at which a substance goes from solid to liquid
Boiling Point: temperature at which a substance goes from liquid to gas
Surface Tension: an invisible net on the surface of water caused by the attraction of
neighboring water molecules.
Molecule: the smallest unit of 2 or more non metals
Chemical bond: what hold elements together in a compound
1. Chemical equation: the short way of describing a chemical reaction using symbols,
formulas and numbers:
Reactant: left side of arrow: see above
Product: right side of arrow: see above
Coefficient: see above
Subscript: see above
Law of Conservation of Mass: states that matter cannot be created or destroyed. Atoms
and mass on left must equal atoms and mass on right.
Exothermic reaction: a reaction in which heat energy is released
Endothermic reaction: a reaction in which heat energy is absorbed
Activation energy: amount of energy needed to start a reaction
Concentration: amount of solute per volume of solvent.
Enzyme: biological catalyst
Inhibitor: slows a reaction (preservative)
Precipitate: a type of evidence showing a chemical change took place: adding 2 liquids
and a solid is produced
Ion: an atom with a charge results from an atom gaining or losing electrons
Valence electrons: the electrons in an atom’s outer most shell
Ionic bond: formed from metal and non metal results from the attraction between unlike
charges after metal loses electrons and becomes positive ion and nonmetal gains
electrons and becomes negative ion.
Ionic compound: a compound which is formed by an ionic bond
Covalent bond: a compound formed when 2 or more nonmetals share electrons
Polar covalent bond: not needed for test
Periodic Table: a chart in which all elements are arranged by atomic number
Group: vertical on periodic table. Similar properties
Period: horizontal on periodic table
Metal: Name 3 properties and where they are located:
Left. Mostly solid, high melting and boiling points, malleable, good conductors
Nonmetal: Name 3 properties and where they are located: right, mostly gases,
nonconductive, brittle
Transition metal (Name 2 facts and where they are located: common metals, groups 312
Alkali metals: 2 properties and what group they are located:
Group 1 reactive, often bond with group 17
Alkali Earth metals: 2 properties and what group they are located: Group 2 reactive,
often bond with group 16
Halogens 2 properties and what group they are located: Group 17 reactive, often bond
with group 1
Noble Gases: 2 properties and what group they are located:
nonreactive, all gases
27.State the 5 ways to change the rate of a reaction: KNOW WHY AND HOW EACH
OF THEM AFFECT THE REACTION.
Add catalyst: lowers activation energy
Increase surface area: more places for reaction to occur
Increase concentration: more of a chance of reactants reacting
Increase temperature: as particles move quickly, more chance they will collide and react
Inhibitor: slows down a reaction
28.How are mixtures different than compounds? Mixtures not chemically bound, can be
easily separated.
29. 4 Ways to separate a mixture are:
Magnet, filtering, evaporation, distillation
30. Units for Mass: grams
Density: g/ cm3
Volume: cm3 or ml
31.Formula for density: D=m/v
32.Mass= 25 g
Volume= 5 cm3
show work
D=m/v
D=25 g/5 cm3
D=5 g/ cm3
33. Why do certain substances float or sink? Density of water is 1 g/ cm3
.
If substance has a density greater than density of wATER it will sink, If substance has a
density less than the density of wATER it will float.
34. What are the changes that occur to illustrate that a chemical change took place:
Production of gas (bubbles), precipitate, change in temperature, change in property,
change in color, odor
35: Draw the Bohr models for Nitrogen and Aluminum:
36: Draw electron dot models for Nitrogen and Aluminum
1.
1.
37. Name this compound: CaCl2: calcium chloride
38. Name 3 Properties of ionic compounds: metal-nonmetal, usually solid at room
temperature, high melting point, conductive in water
39. Name 3 Properties of covalent compounds: nonmetal-nonmetal , usually liquids and
gases at room temperature, low melting point, non conductive.
40. What is the relationship between temperature and volume of a gas? As temperature
of a gas increases so does its volume.