Chemistry Flashcards
The study of matter.
Its chemical and physical properties and the chemical and physical changes it undergoes.
Chemistry
A specific substance that can’t be broken down into simpler substances by chemical reactions.
Element
Organized the elements into a periodic table.
Dmitri Mendeleev
Composed of atoms.
Matter
The smallest component/unit of an element that retails all of the chemical and physical properties of the element.
Contain a nucleus which contains protons and neutrons and is surrounded by electrons.
Atom
Central region of an atom.
Contains protons and neutrons.
Nucleus
Positively charged particles.
Located within the nucleus.
Protons
Particles with no electric charge.
Located within the nucleus.
Neutrons
Negatively charged particles.
Scattered around the outside of the nucleus in rings.
Electrons
Outer ring of electrons.
Important for chemical reactions.
Valence Electrons
# of protons + (average) # of neutrons
Atomic Mass
When an atom contains the same amount of protons and electrons, the positive and negative charges balance each other.
The atom is neutral.
Devised the original model of the atom, which depicted atoms like a solar system.
Niels Bohr
Atoms of the same element have the same number of protons and electrons but can have different numbers of neutrons.
Chemically identical, but may have different stabilities.
Isotopes
Result from the charges on 2 atoms interacting with each other (elements join and their atoms are held together).
3 main kinds: ionic bonds, covalent bonds, and hydrogen bonds.
Chemical Bonds
The electrons in the outermost energy levels.
These are the electrons that interact with other atoms.
Valance Electrons
One atoms gives electrons to another.
One atom losing 1+ electrons and another atom gaining those electrons.
Lose/gain electrons to achieve stability.
Gain/lose electrons —> Formed between ions of opposite charges.
Ionic Bonds
An atom with a charge.
Ion
Ions with a negative charge.
Anions
Ions with a positive charge.
Cations
Result of ionic bonds.
2 ions of opposite charges —> Attract each other and stick together, making a bond.
Compound
Ionic Compund
Formed when elements share electrons to achieve a full outer shell.
Share electrons, holding the atoms together.
Covalent Bonds
Result when atoms are joined by covalent bonds.
Molecules
When 2 covalently bonded atoms share electrons nearly equally.
Nonpolar Covalent Bonds
Electrons are more attracted to one type of molecule than the other.
Electrons are shared unequally.
A partial positive or partial negative charge developed at each pole (end) of the bond.
Polar Covalent Bonds
A full outer orbital of electrons.
Octet
Lone pairs repel each other (because they have the same charge) and push the hydrogen atoms down to form a v-shape.
Bent Molecule
Created when a molecule has regions of charge that are separated.
Dipole
Molecules with dipoles.
Polar Molecules
Multiple water molecules form weak attractions from the oxygen atom on one molecule to a hydrogen atom in another molecule.
Weak attractions between the slightly negative side of water molecules and the slightly positive side of surrounding water molecules.
Hydrogen Bonds
Reasons why water is extremely important to life (due to hydrogen bonding):
Universal Solvent
Cohesion
Adhesion
Water is attracted to itself.
Ex. Surface tension —> Allows bugs to float on the water surface.
Cohesion
Water is attracted to other substances.
Ex. Towels sparking up water from surfaces.
Adhesion
Positive hydrogens can surround negative ions and negative oxygen pole can surround positive ions.
When the ions of an ionic molecule are more attracted to the water than to each other, they break apart and dissolve.
Universal Solvent
A substance that increases the concentration of hydrogen ions (H+) in a solution.
Donates H+ ions.
pH 0-7
Acid
Releases/provides hydroxide ions (OH-) or other negatively charged ions that combine with hydrogen ions redacting their concentration in a solution.
pH 7-14
Base
Indicates a substance’s acidity (acid) or alkalinity (base).
pH
Alkalinity
Base
