Unit 2 Chapter 2 Basic Chemistry

What is plasma

Ionized gas, high energy, conducts electricity

What is an element

A pure substance that can't be broken down into simpler substances by chemicals

What is carbon

backbone of all organic molecules

What is Hydrogen

Component of water and organic molecules

What is Nitrogen

Amino acids, building blocks of protein, and nucleic acids

What is Oxygen

Cellular respiration and major part in H2O

Phosphorous

Nucleic Acids, ATP, energy for cellular processes

Sulfur

In some amino acids and vitamins

Groups/Families

Elemerts in same group with same number of valence electrons, similar chemical behavior

Periods

Properties of element gradually change across period, from metallic to nonmetallic

Atom

Smallest unit of matter

what does an atom have

nucleus, proton, neutron, electron

Atomic number

Number of protons/electrons

Atomic Mass

number of protons and neutrons

Stable Isotopes

Don't change overtime

Radioactive Isotopes

Unstable, decay over time, release energy particles

Alpha decay

Emit alpha particles

How much penetration can alpha decay do

low

Beta decay

neutron turn into proton, release beta particle, and an antineutrino

Does beta decay mass stay the same

yes

How much does the beta decay atomic number increase and how much penetration

moderate

Gamma decay

pure energy, after alpha or beta decay

Does gamma decay have a change in mass or atomic number? How much penetration

no, extremely high

Half-life

Amount of time it takes for half of atoms in radioactive sample to decay into stable form

Do Isotopes have the same half-lives

no

What do valence electrons determine

reactivity and bonding

Compound

Molecules with two different elements bonded

Are all compounds molecules and are all molecules compounds

yes, no

Molecular formula

Represents types and number of atoms in molecules

Structural formula

arrangement of atom and the bonds between them

Ionic bonds

When electrons are transferred from one atom to another

Covalent bonding

Bonds formed by sharing electrons between atoms, make each atom have full valence shells

Polar bonding

Electron shared unequally

Nonpolar bond

Equally shared electrons

Dipole Molecule

Slightly positive, slightly negative

Hydrogen bonding

weak attract between hydrogen atom already covalently bonded to high electronegative to other electronegative

Water structure

Bend, polar, dipole

cohesion

sticking together of same molecules bc of hydrogen bonding, surface tension

Adhesion

sticking to other surfaces, water moves up

High heat of vaporization

Takes lots of energy to change liquid into gas, cools organism body

Density of ice

less dense than liquid water

Hydrophilic

loves water, dissolves in it

hydrophobic

fears water, doesnt dissolve

acids

substance that donates hydrogen ions in a solution, increasing the concentration of H

strong acid

completely dissociates in solvent

weak acids

partically dissociates in solvent, exists in equilibrium

what can weak acids do

pH stability

bases

substances that accept hydro ions or release hydrooxide ions, reduce concentration of H

strong bases

completely dissociates in solvent

Neutralization reactions

chemical reaction where acid and base combine to form a salt and water

buffers

maintain stable pH in solution by resisting sudden changes in H

how do buffers shift

left or right depending on H

what do buffers help maintain

homeostasis