Chemistry Flashcards
Fundamentals of chemistry
Atoms
Definition + components
The most basic unit of all matter. Neucleus surrounded by subatomic particles.
Subatomic particles
List them
- Protons
- Neurons
- Electrons
Protons
charge / mass / location on atom
Subatomic particle
+1 charge / 1 mass / stuck in the in nucleus
* Number dictates it’s element
Electrons
Subatomic particle
-1 charge / «<1=0 / travels around the nucleus
- moves easily between atoms
- charge changes when added or removed
Neurons
Subatomic particle
0 charge / 1 mass / stuck in the nucleus
What is the charge of an atom?
protons - electrons
= charge
What is the mass of an atom?
of protons - # of neurons
= mass
What are elements?
Different types of atoms that have different chemical properties.
The # of protons determines what element an atom is and the charge of its nucleus.
The # of neurons and electrons can be different between different atoms of the same element.
Periodic table of elements
Table that shows all elements known to man, each square is a different element.
Contains:
* Name of element (not always)
* Atomic # = # of protons in the nucleus
* Atomic symbol = 1 capital letter or 1 capital + 1 lower case
* Atomic mass = mass of atom, #protons + #neurons
Electron Shells
3 orbiting shells of electrons around the nucleus.
1st shell has 2 electrons
2nd shell has 8
3rd has 8
What do atoms want?
2 things:
1. The outer shell to be full
2. A neutral charge (# of protons = # of electrons)
What are right column atoms?
Noble gasses
Generally don’t interact with other elements & have a full outer shell (same # of protons and electrons)
What are ions?
Atoms on a small molecule with an electrical charge.
The # of protons + electrons are different but make a full outer shell.
Anions
Ions with a negative cahrge.
protons < electrons
Cations
Ions with a positive charge
protons > electrons
Ionic bond
When possitive and negative ions attract and form a bond.
(-)Anion + (+)Cation –> negative attracts positive
ex: table salt - NaCl
List of important ions
Name + Periodic lable
- Sodium - Na+
- Chloride - Cl-
- Potassium- K+
- Calcium - Ca++
- Magnesium - Mg ++
- Iron - Fe (2+ or 3+)
What is a covalant bond?
2 atoms held together by sharing electrons.
This allows atoms to have a full outer shell with a neutral charge, forming a bond stronger than ionic bonds.
Single bond
2 atoms sharing 2 electrons
ex: H-H / H-O-H
Double bond
2 atoms sharing 4 electrons
ex: O=O (molecular oxygen)
What are molecules?
2 or more atoms held together by a covalant bond
Molecular formula
Refers to how many atoms in each element are found in molecules. It’s expressed at the bottom right
Polar Covalent Bonds
Covalent bond where 2 atoms don’t share electrons equally
* Atom pulls more has slight negative (-) charge
* Atom that less has slight positive charge
Chemical Reactions
Occur when molecules change into different molecules.
The arrangement of atoms into molecules changes but the number of atoms of each element doesn’t change.
Water
Components
- Made of 2 hydrogen + 1 oxygen
- Hydrogens are at an angle from each other, not on opposite sides of oxygen
Dipole
A polar bond with one molecule slightly positive and one slightly negative.
Hydrogen Bonds
Bonds between (not within) different water molecules + in other places too.
Like ionic bonds + attracts =weaker
Hydrophilic
Water-loving substances that disolve in water.
* Charged on polar substances
* Slight charges on water molecules are attracted to charges on hydrophilic substances
Hydrophobic
water-fearing
* Substances that don’t disolve in water.
* non-polar substances
Acids
Substances that release H+
More H+ released, the more acidic + lower the pH
Bases
Chemicals that absorb H+ with a high pH.
pH
Refers to the measure of how acidic or basic a solution is.
1. Acidic: pH <7, #H+ > OH-, lower pH = more acidic
2. Neutral: pH = 7, pure water
3. Basic: pH > 7, #H- < OH- higher pH = less acidic
Organic Molecules
Molecules with Carbon and Hydrogen bonds.
Living things are made of organic molecules.
(I Carbon makes 4 bonds, forming the backbone of all organic molecules
Hydrogen makes 1 bond, found all over all organic molecules
C-C and C-H bonds are non-polar)
Other elements in biological organic molecules
- Oxygen (O) - 2 bonds
- Nitrogen (N) - 3 bonds
In many organic molecules but not all
Both form polar bonds
Molecules with lots of O + N = hydrophobic - Phosphorus (P)
- Sulfur (S)
Not as common as O + N
Inorganic carbon molecule
Carbon Dioxide (CO2)
What is energy?
Doing things or the ability to do things
* Can never be created or destroyed
* Can be changed from one form to another
Ex: drop something
Loses gravitational energy as it gets lower
Gains kinetic energy as it goes faster
Turning gravitational energy into kinetic energy
Kinetic Energy
The energy of something moving.
The faster something goes + the more it weights = + kinetic energy it has
Heat energy is a form of kinetic energy
ex: How fast chemicals are moving in the solution/ substance
Electromagnetic radiation
Light
Potential Energy
Energy based on something’s position.
Gravitational Energy
Energy based on somethings relationship to Earth’s core.
further from Earth -> ^ gravitational E
Chemical Energy
Energy in chemical bonds
* Bigger molecules have more energy - How we get energy from food
* Different bonds have different amounts of E
* Breaking bonds to make new ones changes the amount of E in molecules
Reactants
Chemicals at the beginning of a process.
Products
Chemicals at the end of reactions.
Exergonic reactions…
release Energy.
* E of reactants > E of products
Spontaneous reactions - can happen without any other E
Endergonic reactions…
take in Energy.
E of reactants < E of products
Metabolism
refers to all chemical reactions that happen in the body.
1. Anabolism
2. Catabolism
Catabolism
breaks big molecules into smaller ones.
Exergenic reaction = releases E
Anabolism
makes big molecules out of smaller molecules.
Endergonic reaction = requires E
Metabolism
In relation to digestion
- Catabolism - to get energy
- Move things
- Build large molecules (Anabolism)
Electrochemical Gradient
Energy from there being different concentrations of chemicals + different charges on either side of the plasma membrane.
Chemical Equilibrium
When reactions reach a certain ratio of reactants to products and stop.
The further you are from equilibrium - the faster the reactions
^ Reactants –> Equilibrium –> ^ rate of reaction
V Products –> Equilibrium–> ^ rate of reaction
