Flashcards in Chapter 2 Deck (54):
Anything that occupies space and has mass.
Is a substance that cannot be broken down to other substances by ordinary chemical means. (92 in nature)
Is a substance consisting of two or more different elements combined in a fixed ratio.
make up 96% of all living matter.
Oxygen, Carbon, Hydrogen, and Nitrogen
Are essential for humans, but only in minute quantities.
causes the thyroid gland to grow to abnormal size, a condition called goiter.
commonly added minerals to food
Iron , Fluoride
Is the smallest unit of matter that still retains the properties of an element
Is a subatomic particle with a single positive electrical charge. (+)
Is a subatomic particle with a single negative charge. (-)
Is electrically neutral. (no charge)
atoms central core. (2 Protons, 2 Neutrons)
All the atoms of a particular element have the same unique number of protons.v
Is the sum of the number of protons and neutrons in its nucleus.
is approximately to its mass number the sum of its protons and neutrons in daltons.
Mass number vs atomic mass
All atoms of an element have the same atomic number, but some atoms of that element may differ in mass number. (This is because of Isotopes)
The different isotopes of an element have the same number of protons and behave identically in chemical reactions, but they have different numbers of neutrons.
is one in which the nucleus decays spontaneously, giving off particles and energy
use of isotopes
isotopes can be used to track certain body functions by finding where the isotopes are in the body.
the location of electrons from the nucleus, each with a characteristic distance.
first orbital and second orbital
The first orbital can hold 2, the second can hold 8 (4 pairs).
is the number of electrons present in the outermost shell
when two atoms with incomplete outer shells react, each atom will share, donate, or receive electrons so both have complete outer shells.
two atoms, each with an unpaired electron in its outer shell, actually share a pair of electrons.
Are atoms held together by covalent bonds.
Valence or bonding capacity
is the number of additional electrons needed to fill its valence shell.
an atom’s attraction for shared electrons.
Non-polar covalent bonds
electrons that are shared equally between the atoms.
Polar covalent bond
the pulling of shared negatively charged electrons closer to the more electronegative atom makes that atom partially negative and the other atom partially positive. (electron not shared equally)
an atom or molecule with an electrical charge resulting from a gain or loss of one or more electrons.
Two Ions with opposite charges attract each other.
Ionic bonds form
when one atom transfers an electron to another.
a synonym for an ionic compound (Sodium Chloride).
The fullness of a valence shell
determines the pattern of covalent bonding or ionization.
Most strong bonds
one of the most important types of weak bonds
what are the charges in a hydrogen bond
Oxygen slightly negative, Hydrogen slightly positive.
it has an un-equal distribution of charges
breaking existing chemical bonds and forming new ones.
Tendency of molecules of the same kind to stick together.
the cling of one substance to another.
a measure of how difficult it is to stretch or break the surface of a liquid.
is the energy associated with the random movement of atoms and molecules.
thermal energy transferred from warm to cold.
measures the intensity of heat, that is the average speed of molecules in a body of matter.
when a substance evaporates the surface of the liquid that remains behind cools down.
is a liquid consisting of a uniform mixture of two or more substances.
The dissolving agent
a substance that is dissolved
is one in which water is the solvent
Why is water a universal solvent
Positive hydrogen ends of water molecules attract to negative ions.
Negative Oxygen ends of water molecules attracted to positive sodium ion.
Donates hydrogen ions (H+)
is a substance that reduces the hydrogen ion concentration of a solution. (OH-)