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37 terms

Science Vocab

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hypothesis
an educated assumption or guess concerning the results of a given experiment
dependent variable
something that relies on other factors in the experiment
independent variable
stands alone and isn't changed by other variables one is trying to measure
control group
a baseline group used to reference back to when comparing results of experiment to original group
experimental group
group exposed to the variable of the experiment
scientific theory
a concept that explains scientific observations
positive feedback loop
a closed system, response of the system relies on the feedback signal to function
negative feedback loop
feedback that reduces the output of a system
anthropogenic
caused or produced by humans
atom
the smallest component of an element; a very small particle of matter
molecule
consists of one or more similar atoms in an element; in a compound it is two or more different atoms
elements
cannot be separated into simpler substances by chemical means
compounds
composed of two or more parts or elements
proton
location: nucleus
charge: positive
neutron
location: nucleus
charge: none
electron
location: valence shells
charge: negative
atomic number
the number of protons in the nucleus of an element
mass number
total number of neutrons and protons in a particular atom
isotopes
a form of a given element that has the same number of protons, but a different number of neutrons
ion
formed by the loss or gain of one or more atoms
cation- positive ion
anion-negative ion
pH
hydrogen ion concentration in gram atoms per liter
acids: 1-6
neutral: 7
bases: 8-14
organic compound
any blend of carbon and another element
inorganic compound
any blend that does not contain carbon
prokaryotic
cellular organism that has: no nuclear membrane, no organelles in the cytoplasm except ribosomes, and genetic material is in the form of single continuous strands forming coils or loops
eukaryotic
specialized organelles in cytoplasm, membrane bound nucleus enclosing genetic material organized into chromosomes, system of division by mitosis or meiosis
genes
basic physical unit of heredity; linear sequence of nucleotides along segment of DNA, which provides instructions for synthesis of RNA, translates into proteins, > character
chromosomes
threadlike bodies consisting of chromatin that carry genes in a linear order
Law of Conservation of Matter
matter cannot be created nor destroyed in an isolated system
radioactive isotopes
several species of the same chemical element with different masses whose nuclei are unstable, dissipate excess energy by emitting radiation in the form of alpha, beta, and gamma rays
half life
time required for 1/2 of the atoms of a given amount of a radioactive substance to disintegrate
nuclear fission
splitting of an atomic nucleus into almost equal parts, usually with an associated release of energy
nuclear fusion
two nuclei combine to form a nucleus with the release of energy
kinetic energy
energy of a body or system with respect to the motion of the body or system
potential energy
energy of a body or system with respect to its position
heat
form of energy associated with the motion of atoms or molecules
1st Law of thermodynamics
when heat flows to or from a system, the system gains or loses an amount of energy equal to the amount of heat transferred
(heat added= incr. internal energy + external work by system)
2nd Law of thermodynamics
heat of itself never flows from a cold object to a hot object