cset subtest 2 science

science yay

boyles law

pressure increases, volume decreases

sublimation

transition from solid to gas phase (ex. dry ice)

mass

amount of matter in chemical substance

density

mass/volume

hardness

refers to property of matter in the solid phase that gives it high resistence to its shape changing when force is applied

scratch hardness

resistance to fracture or permanent deformation due to friction from a sharp object

indentation hardness

resistance to permanent deformation due to a constant load from a sharp object

rebound hardness

height of bounce of an object dropped on the material, related to elasticity

Moh’s scale of hardness

rates minerals and puts them on a scale 1-10 determined by the ability of a hard material to scratch a softer material (ex. talc at 1 and diamond at 10)

physical properties

characteristics that make up physical composition of a substance (color, form, electrical conductivity, density)

physical changes

do not involve one substance changing into another, but rather changes in state

chemical changes

substance is changed into something else

chemical reactions

show number of molecules of reactants and products

nucleus

center of atom, made up of protons and neutrons

protons

positive electric charge

neutrons

no charge

electrons

move around the nucleus in clouds, with a negative charge

chemical elements

cannot be separated into different substances;assigned atomic numbers equal to number of protons in the nucleus of their atoms

compounds

formed by chemical combination of one or two more elements in a fixed ratio

periodic table of elements

arranges known elements from left to right and top to bottom in order of increasing atomic number; rows arranged sp elements with similar properties fall into the same vertical columns to form groups

atomic mass

protons+neutrons

pH

measure of acidity/basicity of a solution

litmus

blue turns red under acidic conditions (ex. battery acid, lemon juice, vinegar); red turns blue under basic conditions (ex. soap, ammonia, lye)

mixture

two+ materials combine together without a chemical reaction occuring

velocity

rate of change of position with time

acceleration

rate of change of velocity with time

newton’s first law

without outside forces, a stationary object will never move. without outside forces, an object in motion will never stop or deviate from its course

newton’s second law

the more force, the more acceleration

newton’s third law

for every action, there is an equal and opposite reaction

gravitation

natural phenomenon by which objects with mass attract one another

magnetism

north pole attracts south pole, but like poles repel each other; iron fillings area attracted to either pole; electric current, earth’s field

simple machine

mechanical device that changes direction or magnitude of a force; defined as the simplest mechanisms that use mechanical advantage/leverage to multiply force

mechanical advantage

ratio of the output to the input force

lever

rigid object used with an appropriate fulcrum/pivot point to multiply the mechanical force that can be applied to another object (ex. scissors, wheelbarrow, baseball bat)

pulley

mechanism composed of a wheel with a groove between two flanges around the wheels circumference. a rope usually runs inside the groove. used to change the direction of an applied force, transmit rotational motion, or realize mechanical advantage in either a linear or rotational system of motion

inclined plae

flat surface whose endpoints are at different heights resulting in a slope, allowing less force to be exerted

screw

inclined plane that can convert rotational force into a linear force, increasing mechanical advantage

forms of energy

solar, chemical, electrical, magnetic, nuclear, sound, light, electromagnetic

energy

ability to perform work

kinetic energy

energy possessed by a moving object

electricity

form of energy that can produce sound, heat, light and power; exists where number of negative electrons does not precisely equal the number of positive protons

electric circuit

path or circuit an electric current flows

static electricity

results when electrical charges build up or increase on the surface of a material, no current flowing (ex. rubbing hair against balloon causes the balloon to become negatively charged while your hair becomes positively charged)

light

light travels in perfectly straight lines as rays

longest-shortest wavelengths

longwave radio, shortwave radio, microwaves, infrared, visible light (red, orange, yellow, green, blue, violet), ultraviolet, xrays, gamma rays

nuclear energy fission

releases energy when a heavy nucleus splits into smaller fragments; used in power plants and atomic bombs

nuclear energy fusion

yields energy when light nuclei unite to heavier nucleus; used in huydrogen bombs and stars

celsius freezing/boiling points

0 degrees=freezing, 100 degrees=boiling

fahrenheit freezing and boiling point

32 degrees=freezing, 212 degrees=boiling

heat conduction

spontaneous transfer of thermal energy through matter from a region of higher temperature to a region of lower temperature

thermal radiation

electromagnetic radiation emitted from the surface of an object due to the object’s temperature (ex. electric heater)

convection

hot air is less dense than cool air, hot air rises

incandescent light bulb

source of electric light that works by incandescence (electric current passes through a thin filament, heating it until it produces light; enclosure prevents oxygen from oxidizing and destroying light of hot filament)

fluorescent lamp

gas discharge lamp using electricity to excite mercury vapor, excited mercury atoms produce shortwave ultraviolet light that causes a phosphor to fluoresce, producing visible light

refraction

objects appear bent as light passes from one transparent object into another, also responsible for rainbows and splitting white light into a rainbow spectrum

optics

refraction occurs when light waves travel from a medium with a given refractive index to a medium with another index

reflection

occurs when light travels only in straight lines

renewable energy

energy generated from natural resources—like sunlight, wind, rain, tides, and geothermal heat—which are naturally replenished

nonrenewable energy

taken from finite resources that will eventually dwindle becoming too expensive/too environmentally damaging to retrieve—including fossil fuels like coal, petroleum and natural gas, contributing to global warming (CO2 and methane are GHG)

algae

range from single cell to huge seaweed

fungi

lack chlorophyll, cannot manufacture food; either parasites that prey on other living organisms or saprophytes existing on waste products/decaying organisms

lichens

2 organisms, fungus and alga, living together symbiotically

ferns

lack seeds, reproduce by spores, develop into new plants without fertalization

gymnosperms

cone bearing plants, including pines with seeds exposed on cone scales

angiosperms

flowering plants that bear seeds within their fruits

ovule

small egg; structure that gives rise to and contains the female reproductive cells, after fertilization develops into a seed

flowering plant ovule

contained within the flower, in the ovary (which becomes the fruit)

photosynthesis

metabolic pathway that converts light energy into chemical energy—plants use energy in sunlight to convert carbon dioxide from the atmosphere plus water into simple sugars

cell

smallest amount of living matter that is the unit of structure/function for all organisms

cell membrane

semi permeable, allowing some substances to pass while excluding others

cytoplasm

main material inside the cell, containing functional bodies like the centrosome (participates in cell division), ribosomes (construct proteins), mitochondria (conduct metabolism), golgi bodies (involved in secretion), vacuoles (involved in digestion), plastids (for plants, bodies with chlorophyll for photosynthesis)

nucleus

membrane closed structure found in eukaryotic cells containing most of cell’s genetic information, controlling growth and reproduction

chloroplasts

organelles found in plant cells and eukaryotic algae that conduct photosynthesis

mitochondrion

power plant of the cell, generating most of the cell’s supply of ATP, used as source of chemical energy—involved in other processes like signalling, cellular differentiation, cel death

herbivores

eat plants

carnivores

prey on animals

digestion

breaking down of chemicals in the body into a form that can be absorbed

how do carbohydrates convert to various sugars?

by action of enzymes including those from saliva

how do fats transform into glycerol and fatty acids?

by action of bile from the liver and enzyme lipase from the pancreas

proteins in the process of digestion

broken apart to their constituent amino acids

final products of digestion

sugars, glycerol, fatty acids, amino acids

where do the final products of digestion go?

absorb into the bloodstream by millions of villi lining the small intestine

what happens when digestion products are absorbed into the blood?

molecules are metabolized in various body tissues

when does preparation for digestion begin for mammals?

saliva in mouth and digestive enzymes in stomach

how is food broken down in the stomach?

churning and mixing food with enzymes

where does food go after being processed in the stomach?

small intestine

small intestine

where the majority of digestion and absorption takes place

circulatory system

organ system that moves nutrients, gases, and wastes to and from cells, helps fight diseases, stabilizes body temperature and pH to maintain homeostasis

cardiovascular system

contains blood, heart, blood vessels; distributes blood

lymphatic system

contains lymph, lymph nodes, lymph vessels; distributes lymph

main components of human (closed) circulatory system

heart, blood, blood vessels

pulmonary circulation

loop through lungs where blood is oxygenated

systematic circulation

loop through the rest of the body to provide oxygenated blood

how much blood does an average human contain?

5-6 quarts

what does blood contain?

plasma, red blood cells, white blood cells, platelets

how do the digestive and circulatory system interacct?

provide nutrients the system needs to keep the heart pumping

red blood cells function

transport oxygen in combination with the iron pigment, hemoglobin

white blood cells function

fight infection

platelets function

initiate clotting to stop bleeding

plasma function

nutrients, wastes, hormones, antibodies, and enzymes dissolved in plasma