Chapter 2 Test Vocab Flashcards
Matter
Anything that occupies space and has mass—> found as liquids, solids, and gas
Elements
A substance that cannot be broken down by other substances by ordinary chemical means
Compound
A substance consisting of two or more elements in a fixed ratio
Trace Elements
a chemical element present only in minute amounts in a particular sample or environment.
a chemical element required only in minute amounts by living organisms for normal growth.
Organisms
Made up of matter
Matter is….
made up of elements
How many elements are there?
92
Isotope
An element that has the same # of protons but different # of nuetrons
(most stable, some radioactive)
What 4 elements make up 97% of us
carbon, oxygen, hydrogen, nitrogen (NOCH)
Trace elements are….
essential in smaller quantities (ex. iodine, florine, iron)
all elements are electrically…
1. negative
2. positive
3. nuetral
- nuetral
Atom
The smallest unit of matter that still retains the properties of an element
Subatomic particles
protons, neutrons, electrons
Atomic Number
The number of protons in an element (same number of protons and electrons)
Atomic Mass
the sum of protons and neutrons
The unit of measurement for atomic mass
dalton
mass of protons and neutrons
1 dalton
mass of electrons
1/2,000 of protons and neutrons, barely contributes to the mass of an atom
stable isotopes
nuclei remain intact forever
radioactive isotopes
nucleus decays randomly, gives off particles and energy
Matter cannot be
A. broken down any further
B. expanded any further
A. broken down any further
Proton charge, mass, and location
Charge: (+)
Mass: 1 amu
Location: nucleus
Neutron charge, mass, and location
Charge: (o)
Mass: 1 amu
Location: nucleus
Electron charge, mass, and location
charge: (-)
mass: 1/2000 amu
location: electron shells
Two famous radioactive elements
oxygen, glucose
common trace element in the body
zinc
false statement regarding matter
all matter exits in the form of compounds
makes up a molecule of water
2 hydrogen, 1 oxygen
Radioactive compounds can be used in….
the metabolic process
Postitive use of radioactive compounds
MRI’s
NEGATIVE use of radioactive compounds
atomic bombs
Involved in an atom’s chemical activity
A. Protons
B. Neutrons
C. Electrons
C. Electrons
Electron Shell
Where electrons are located
Periodic Table: Columns/Groups
vertical, number of valence electrons, charge
Periodic Table: Periods
Horizontal, determine the number of electron shells
Ionic Bond
The transfer of electrons between atoms
Covalent Bonds
The sharing of electrons between atoms
Valence electrons
The electrons on the outermost shell of the atom
Chemical Bonds
Hold atoms together
Noble Gases
8 valence electrons
Molecule
two or more atoms held together by COVALENT bonds
Electronegativity
The measurement of an atoms attraction for shared electrons (in covalent bonds, = electronegativity allows them to share electrons)
THE HIGHER THE BETTER
Non polar covalent bonds
atoms of the same element, equal electronegativity, strongest bond
Polar covalent bonds
Two atoms differ in electronegativity- one NEGATIVE charge, 1 POSITIVE charge
Covalent bonds are
A. stronger than ionic bonds
B. weaker than ionic bonds
A. Stronger than ionic bonds
Anion
Negative, gains electrons
Cation
Positive, gives electrons
Ion
An atom or molecule with an electrical charge after gaining or losing electrons
-causes the atom to have an electrical charge
Ionic Bonds
Attraction between two ions with opposite charges, the resulting compound is electrically neutral
Hydrogen Molecules
Made with water molecules
Polar Molecule
An unequal distribution of charges
Chemical Reaction
Breaking existing chemical bonds and forming new ones, changes one set of chemicals to another set of chemicals
Don’t create destroy matter, only rearrange it
Reactants
The conversion of the starting materials
Product
The material from the chemical reaction
Cohesion
Molecules of the same kind stick together
Adhesion
When two substances stick togther
Surface Tension
How difficult it is to break the surface of the liquid
Thermal energy
Energy associated with the movement of atoms and molecules
Heat
The thermal energy in transfer from a warmer to a cooler body of matter
Evaporate
changes the physical state from liquid to gas
Evaporative cooling
The surface of water cools down
3 Forms of water
liquid, solid, gas
Solution
A liquid consisting of a mixture of two or more substances
Solvent
The liquid that gets dissolved into
Solute
The substance dissolved
Aqueous solute
The water is the solvent
The pH scale acids:
Contains H+, donates H+ to solutions, 1-6 on the pH scale
The pH scale base
OH-, reduces H+ in a solution, 8-14 on the pH scale
Buffer
Limits the amount of changes in pH
