chapter 2 biology test Flashcards
A substance that cannot be broken down into anything else
Element
Composed of two or more elements that are chemically combined (not a mixture)
Compound
Protons + neutrons
Atomic mass
____ of an atom have a different number of neutrons which vary their atomic mass
Isotopes
____ elements have a full outer shell so they don’t react with other elements
Inert
The atoms boned by and ionic bind are called a __________
Formula unit
____ bonds form when electrons are shared between two elements
Covalent
Two or more atoms held together by covalent bonds
Molecule
Covalent bonds are _____ than ionic bonds
Stronger
An atoms attraction for electrons
Electronegativity
_____ covalent bonds form when there is an unequal sharing of electrons
Polar
Covalent bonds have an equal sharing of electrons between two atoms of the same elements
Non polar
Weak attraction between polar molecules (usually water)
Hydrogen bonds
Acids have a pH ____ than 7
Less
Bases have a pH _____ 7
Above
_____ allows water molecules to form hydrogen bonds with each other
Polarity
The properties of wanted help it support ____
Life
Hydrogen bonds hold water molecules together
Cohesion
Attraction between water and other polar substances
Adhesión
Cohesion + adhesion =
Capillary action
Water has a ____ surface tension
High
A measure of how difficult it is to break the surface of a liquid
Surface tension
Waters high surface tension is caused by the extra storms ___ at its surface
Cohesion
The amount of energy required to raise the temperature of 1 gram of a substance by 1 degree Celsius
Specific heat
Water has a ___ because it can absorb a large amount of energy with only a slight temp change
High specific heat
High specific heat allows water to ___ its temperature
Moderate
Water is an almost ______
Universal solvent
_____ and _____ compounds dissolve in water because their molecules are separated by water molecules
Ionic and polar covalent
____ compounds do not dissolve in water and do not combine
Non polar covalent
The human body is mostly made up of what 4 events
Oxygen carbon hydrogen nitrogen
Zinc iron and iodine are examples of
Trace elements
Protons and neutrons are located in the
Nucleus
Electrons surround the nucleus in the___
Electrons cloud
Charge of proton
+1
Charge of electron
-1
Charge of neutron
Neutral
Mass of proton
1
Mass of neutron
1
Mass of electron
0
Number of protons can be determined in the
Atomic number
___ bonds form when one atoms gives a valance electron to another
Ionic
An ionic bond is the _____ between oppositely charged ions
Attraction
Properties of water
– cohesion/adhesion,
high surface tension, ability to moderate
temperature, an almost universal solvent -
