Flashcards in Atoms-Molecules Deck (28):
-Protons (+) Charge
-Neutrons no Charge
-Electrons (-) Charge
Reside within the Atomic Nucleus
They cannot be broken down or converted to other substances.
- they have an atomic # that is determined by the # of protons in the nucleus.
-there are 92
When atoms of the same element have different #'s of neutrons.
- they can be radioactive
Orbits held by electrons around a nucleus.
- 1st shell holds 2 electrons
-subsequent shells can hold 8 electrons
-shells allow for interactions with other atoms.
Two or more atoms chemically joined
A molecule that contains at least two different elements
Where do interactions happen on atoms?
In the outermost shell
-if outer shell is full-no reaction-inert
-if outer shell is not full-will react-reactive
How do atoms gain stability?
By reacting with another atom
-lose an electron- empty shell
-gain electron-fill shell
-share electron-so both atoms have a full shell
Are the basis of life.
-making or breaking of chemical bonds.
Types of Chemical bonds
-van dee walls interaction
Formed between ions
- the atoms lose or gain electrons to become more stable. Therefore become slightly positive or negative.
- the oppositely charged ions are attracted to one another forming ionic bonds.
-water easily breaks these bonds
An atom which has gained or lost an electron.
- imbalance between protons and electrons
- slightly (+) or (-) charge
When two atoms share an electron to both become more stable.
Nonpolar Covalent Bonds
When electrons are shared equally between two atoms of similar electro negativity.
Polar Covalent Bonds
The unequal sharing of electrons between two differing electronegative atoms.
(+) charge of hydrogen is attracted to the (-) charge of another molecule ( like oxygen)
- mostly found between water molecules.
- very weak bonds(individually)
Van der Waals Interactions
As electrons move they create +\- charged regions on a molecule.
When Atoms/molecules are close they interact at oppositely charged regions
- very weak
Molecules with atoms that have one or more unpaired electrons in there outer shells.
- they are very reactive
-will take an electron forcibly from something else-cell membranes/ DNA
- the lost electron from the second molecule creates another free radical.
React with free radicals and make them harmless.
- like vitamin E and C
Essential to life
- a very good solvent
-interacts with or dissolves many substances
What is dissolved in the solvent.
Substances that interact with water.
- have an electrical charge
--ions and polar molecules
Substances that do not interact with water.
Substances that release H+ when dissolved in water.
Substances that release OH- when dissolved
Expresses the degree of acidity
- scale runs from 0-14
-pure water = 7 neutral
-increasing acidity 6.9-1.0
-more basic 7.1-14.0
--each unit is a tenfold change
Compounds that maintain pH
-can accept or give off H+ or OH-
--like bicarbonate (HCO3-)