Atoms-Molecules Flashcards
Subatomic Particles
- Protons (+) Charge
- Neutrons no Charge
- Electrons (-) Charge
Reside within the Atomic Nucleus
Elements
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
Isotopes
When atoms of the same element have different #’s of neutrons.
- they can be radioactive
Electron Shells
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.
Molecules
Two or more atoms chemically joined
Compounds
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
Chemical Reactions
Are the basis of life.
-making or breaking of chemical bonds.
Types of Chemical bonds
- ionic
- covalent
- hydrogen
- van dee walls interaction
Ionic Bonds
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
Ions
An atom which has gained or lost an electron.
- imbalance between protons and electrons
- slightly (+) or (-) charge
Covalent Bonds
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.
Hydrogen Bonds
(+) 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
Free Radicals
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.
Antioxidants
React with free radicals and make them harmless.
- like vitamin E and C
Water
Essential to life
- a very good solvent
- interacts with or dissolves many substances
- polar
Solute
What is dissolved in the solvent.
Hydrophilic
Substances that interact with water.
- have an electrical charge
- -ions and polar molecules
Hydrophobic
Substances that do not interact with water.
- no charge
- nonpolar molecules
- hydrophobic interactions
Acid
Substances that release H+ when dissolved in water.
