Semester 1 Exam Review

Comprehensive Science 3

Chapter 8

#31-32

Chemical Compounds

#31 – Compare and contrast acids and bases (p.216-219) • •

Acids

– Any compound that increases the number of hydronium ions when dissolved in water – Examples: vinegar, acid rain, soda, lemons

Bases

– Any compound that increases the number of hydroxide ions when dissolved in water – Examples: baking soda, ammonia, soap, antacids

#32 – How would you classify a substance with a pH of 7, below a 7, and above a 7? (p.223) • pH – a value that is used to express the acidity or basicity of a system • pH of 7 =

neutral

• pH below 7 =

acidic

• pH above 7 =

basic

Chapter 16

#42-46

Stars, Galaxies, and the Universe

#42 – What makes up the composition of a star? (p. 465) • A star is made up of different elements in the form of gases

#43 – Define apparent and absolute magnitude (p.468) •

Apparent magnitude

– the brightness of a star as seen from Earth •

Absolute magnitude

– the actual brightness of a star

#44 – Define light-year (p.469)

• The distance that light travels in one year (about 9.46 trillion km)

#45 – List the life cycle of stars from the beginning to the end (p.472-473) 1. A star enters the first stage of its life cycle as a ball of gas and dust 2. After a star forms, it enters the second and longest stage of its life cycle, known as the

main sequence 3. Red giants 4. Red supergiants 5. White dwarfs

– can shine for billions of years before they cool completely

Hertzsprung-Russell Diagram (p.474-475)

#46 – Define galaxy (p.478)

• •

Galaxy

– A large group of stars, dust, and gas held together by gravity

Distant vs. early galaxies

– Looking at distant galaxies helps scientists know what early galaxies looked like – Gives scientists an idea of how galaxies change over time

Chapter 17

#47-50

A Family of Planets

#47 – Draw a model of the solar system (p.496-497)

#48 – Define satellite (p.512)

• A natural or artificial body that revolves around a planet – Moons are natural satellites

#49 – Where do comets come from? (p.520-521) • Comets are formed in the cold, outer solar system

#50 – Compare and contrast asteroids, meteroids, and comets (p.520-523) • • •

Comets

– A small body of ice, rock, and comic dust that follows an elliptical orbit around the sun and that gives off gas and dust in the form of a tail as it passes close to the sun

Asteroids

– Small rocks bodies that orbit the sun

Meteroids

– Small rock bodies that travel through space (similar to but smaller than asteroids; most are probably pieces of asteroids)

COMET METEOR SHOWER ASTEROIDS

Chapter 18

#33-35

Cells, Tissues, and Organs

#33 – List the levels of structural organization in multicellular organisms (p.544) 1. Cells 2. Tissues 3. Organs 4. Organ Systems 5. Organisms

#34 – Explain the role of mitosis at the cellular level (p.547) •

Mitosis

– The process of cell division that results in two new nuclei, each of which has the same number of chromosomes

#35 – Why are new cells needed? (p.546) • Cells grow and divide to make more cells – Cell division allows organisms to grow, repair damaged tissues, and reproduce

Other Information

• The Human Organism (p.557) – Some behaviors are a response to stimuli from the environment – Your organ systems allow your body to respond to that stimuli • Example: You may be scared if you saw an accident on the interstate – Your nervous system would cause changes in your body by making your heart pump blood faster

Chapter 19

#36-41

Heredity

#36 – Define heredity (p. 568)

• Heredity – The passing of genetic traits from parents to offspring

#37 – Explain how Punnett squares are used in science. (p.575) • Punnett squares – Used to predict all the possible combinations of offspring from particular parents

#38 – Compare and contrast dominance and recessive traits. (p.574) • Dominance – Occurs when alleles mask the expressions of other alleles (ex. Pp or PP) • Recessive – Describes an allele that will be masked, unless the organism is homozygous for the trait (ex. pp)

#39 – Define incomplete dominance (p.578) • Incomplete dominance – Sometimes one trait is not completely dominant over another; both alleles have some degree of influence

#40 – Look at the snapdragon cross on page 578 – Why were pink snapdragons produced instead of red snapdragons?

Due to incomplete dominance.

#41 – Which types of cells are made during meiosis? (p.582) • Meiosis – A process that produces

sex cells

with half the usual number of chromosomes (23)

Chapter 1

#1-6

The Nature of Science

#1 – List the steps of the scientific method (p.12-18)

#1

1. Ask a question 2. Form a hypothesis 3. Test your hypothesis 4. Make observations 5. Analyze the results 6. Draw conclusions 7. Communicate results

#2 – Define hypothesis (p.15)

• Hypothesis – An idea or explanation that is based on observations and that can be tested

#3 – Explain the information that is given in a good hypothesis. (p.15) • A good hypothesis is one that can be TESTED

#4 – Explain how changing a variable in an experiment may alter the affects of the experiment. (p.16) • Changing a variable may change one or more parts of the experiment, therefore, changing the outcome of the experiment

#5 – Calculate the density of an object with a mass of 20kg and a volume of 10mL. (p.23) •

Density = Mass/Volume

– 20kg/10mL =

2 kg/mL

– 20,000g/10mL =

2,000 g/mL

#6 – Calculate the volume of an object with a length of 10cm, a width of 5cm, and a height of 2cm. (p.23) •

Volume = Length x Width x Height

– 10cm x 5cm x 2cm =

100 cm 3

Chapter 2

#7-8

Science, Technology, and Society

#7 – Define technology (p.42)

• Technology – The application of science for practical purposes; the use of tools, machines, materials, and processes to meet human needs • Who makes technology?

– Has been made by many kinds of people living in various cultures at different times – Every human culture has had its own technology – No matter where technology starts, it will eventually becomes available to people everywhere

#8 – List three ways that scientists use computers and technology. (p.43-45) • MP3 files, mathematical models, collecting and sorting data, lasers

Chapter 3

#9-14

Properties and States of Matter

#9 – Define matter (p.76)

• Matter – Anything that has mass and takes up space

#10 – Define atom (p.76)

• Atom – The building blocks of matter – The smallest unit of an element

#11 – Define the states of matter (p.90-93) • Properties of

Solids

• Particles are tightly packed in a regular pattern • Particles don’t move around easily;

cannot

move past each other • Retain their shape

#11 – Define the states of matter (p.90-93) • Properties of

Liquids

• Particles are close together with no regular pattern • Particles flow and can easily move past each other • Assume the shape of their container

#11 – Define the states of matter (p.90-93) • Properties of

Gases

• Particles are spread out with no pattern • Particles move freely at high speed • Assume the shape of their container

Changes of State

Energy is added (boiling) Energy is removed

#12 – Give an example of a chemical and physical property (p.80-81) • •

Physical Property

– Characteristic of matter that can be observed or measured without the matter going through a chemical change, or a change in identity – Examples: shape, mass, odor, texture

Chemical Property

– Property of matter that describes a substance’s ability to participate in chemical reactions – New substances are created – Examples: reactivity, flammability

#13 – Define the law of conservation of mass (p.84) • Law of conservation of mass – States that mass is not created or destroyed in ordinary chemical and physical changes

#14 – Give an example of a physical change and a chemical change (p.85-87) • •

Physical change

– Any change in which the physical properties of a substance change but the substance’s identity does not – Examples: salt dissolving in water, water freezing, water melting, glass breaking

Chemical change

– When a change occurs and new substances are formed with identities and properties different from the original matter – Examples: paper burning, baking soda mixed with vinegar, photosynthesis, food digesting

Chapter 4

#15-17

Atoms

#15 – List the particles of an atom (p.113-114)

Inside the Nucleus A. Protons

• Positive charge (+)

B. Neutrons

• No charge (neutral)

Outside the Nucleus A. Electrons

• Negative charge (-) • Orbit the nucleus in electron clouds

#16 – Describe the relative size and parts of a nucleus (p.113) • Inside the nucleus – Protons and neutrons • Outside the nucleus – Electrons (in electron clouds)

#17 – Describe the role of the electrons in an atom (p.118) • Electrons are a very small part of an atom’s mass • Form the outer layer of the atom – Important to the atom’s interactions with its environment – Atoms can gain or lose electrons by forming bonds with other atoms

Isotopes (p.115)

•

Isotope

– atoms of the same element that have the same number of protons (same atomic #) but different numbers of neutrons (different atomic mass) – Each element has a limited number of isotopes found in nature – Example: Carbon-12 (atomic mass = 12; atomic number = 6) • Atomic Mass – Atomic Number = 12 – 6 =

6 neutrons

Chapter 5

#18-20

The Periodic Table

#18 – Define the periodic law (p.131) • States that the repeating chemical and physical properties of elements change periodically with the atomic numbers of the elements

#19 – What information is given in each square of the periodic table? (p.132) Atomic Number Element Symbol Element Name Atomic Mass

protons

electrons

protons neutrons

#20 – Why are elements grouped together on the periodic table? (p.131&138) • Periods – horizontal row of elements (from left to right) • Groups – vertical column of elements (from top to bottom) – Also called a family – Each group has the same number of valence electrons and similar properties • Elements classified as

metals

,

nonmetals

, and

metalloids

Chapter 6

#21-24

Chemical Bonding

#21 – Define chemical bonding (p.158) • What is

chemical bonding

?

• The joining of atoms to form new substances • What is a

chemical bond

?

• An interaction that holds two atoms together • What happens when chemical bonds form?

• Electrons are shared, gained, or lost

#22 – Define valence electrons (p.159) • An electron in the outermost energy level of an atom

#23 – What role do valence electrons play in whether an atom bonds to another atom or not? (p.160-161) • The number of valence electrons determines whether or not an atom will bond –

8 valence electrons

complete set in the outer shell is a – Atoms want 8 valence electrons to be happy!

• To achieve this, atoms will gain, lose, or share electrons

• • • #24 – What are the role of the electrons in ionic bonds, covalent bonds, and metallic bonds? (p.162, 166, 169)

Ionic Bonding

– A bond that forms when valence electrons are transferred from one atom to another atom –

Metal

atoms lose one or more valence electron and

nonmetal

atoms gain electrons

Covalent Bonding

– A bond formed when atoms share one or more pairs of valence electrons – Occurs between nonmetals

Metallic Bonding

– A bond formed by the attraction between positively charged metal ions and the electrons in the metal – Occurs between metals

Chapter 7

#25-30

Chemical Reactions

#25 – Define chemical reaction (p.182) • A process in which one or more substances change to make one or more new substances – Chemical and physical properties of new substance are

different

from the original substances

• #26 – List two signs of a chemical reaction (p.183)

Signs of Chemical Reactions

• Gas Formation • Energy Change • Color Change • Solid Formation –

Precipitate

: a solid that is produced as a result of a chemical reaction in solution

#27 – What happens to the bonds of substances during chemical reactions? (p.184) • How do new substances form in a chemical reaction?

–

First

, the chemical bonds in the starting substances must break –

Then

, the atoms rearrange – Finally, new bonds form to make the new substances

#28 – Compare and contrast endothermic and exothermic reactions (p.196-197) • •

Exothermic Reactions

– A chemical reaction in which energy (heat) is released – Energy released is written as a product • X + X X +

energy Endothermic Reactions

– A chemical reaction in which energy is taken in – Energy taken in is written as a reactant • X + energy X + X

#29 – Define the law of conservation of energy (p.197) • Law of conservation of energy – Energy cannot be created or destroyed, but can be changed or transformed from one form to another – Energy in = energy out

#30 – Explain how the factors affecting the rates of reactions alter the chemical reaction (p.199-201) • • • • •

Temperature

– Higher temperatures = faster rate of reaction

Concentration

– Higher concentration = faster rate of reaction

Surface Area

– Increased surface area of a solid = faster rate of reaction

Inhibitors

– Substance that

slows down

reaction or

stops

a chemical

Catalysts

– Substance that

speeds up

permanently changed a reaction without being