Bio Ch 1-5

tissues Organs are composed of two or more different types of tissues.

prokaryotes and eukaryotes Prokaryotic cells lack the nucleus and other organelles found in eukaryotic cells.

can be manipulatedby the scientists

cannot be changed by the researcher

factors that can change in a value under different conditions

substance that cannot be broken down to other substances by chemical reactions

substance consisting of two or more elements in a fixed ratio

8 neutrons in the nucleus. The atomic number (7) gives the number of protons, and the mass number is the number of protons plus neutrons.

With electrons on the surface, atoms repel one another when they come too close. Thus, electrons determine the space that an atom occupies.

The outer occupied shell is the valence shell, and outer shells hold electrons at higher energy than inner shells.

the same number of protons. The number of protons defines a chemical element. The number of neutrons and electrons can differ among atoms of the same element.

C; it has 6 protons. Atoms represent the element carbon (C) if they have six protons.

10 neutrons. Isotopes have the same number of protons; different numbers of neutrons.

an atom has too many neutrons. The atomic nucleus becomes unstable if the ratio of protons to neutrons is too far from unity.

smallest unit of matter that still retains the properties of an element

no electric charge

positive charge

negative charge

how neutron mass and proton mass are measured 1 neutron ? 1 proton = 1 dalton, or amu

number of protons in its nucleus

sum of protons plus neutrons in the nucleus

the atoms total mass, approximated by the mass number

two atoms of an element that differ in number of neutrons

decay spontaneously giving off particles and energy

capacity to cause change

energy that matter has because of its location or structure

sharing of a pair of valence electrons by 2 atoms

is a molecule that contains at least 2 different elements

atom with an electrical charge resulting from gain or loss of electrons

+

-

attraction between an anion and a cation

forms when a hydrogen atom covalently bonded to one electronegative atom is attracted to another electronegative atom

are attractions between molecules that are very close together

is one in which electron pairs are shared

molecule

two or more atoms held together by covalent bonds.

are the making and breaking of chemical bonds

the starting molecules of a chemical reaction

the final molecule of a chemical reaction

is reached when the forward and reverse reactions occur at the same rate

the relative concentrations of reactants and products do not change

hydrogen

are different ions ions are charged atoms

ionic

an attraction between ions of opposite charge