biology Ch 2
Card Set Information
biology Ch 2
things to know for tests
A particle that is a fundamental building block of all matter.- tiny particles that are building blocks for all substances
positively charges subatomic particle that occurs in the nucleus of all atoms.
Uncharged subatomic particle in the atomic nucleus.
Core of an atom; occupied by protons and neutrons.
Negatively charged subatomic particles that occupies orbitals around an atomic nucleus.
Electrical property. Opposite charges attract, and like charges repel.
Number of Protons in the atomic nucleus; determines the element.
A pure substance that consists only of atoms with the same number of protons.( most common are: O, Cl, N, C, H, P, Cu, Fe, Mg, Ca, Na, K.)
A tabular arrangement of the elements by atomic number.
Forms of an element that differ in the number or neutrons their atoms carry.
Total number of protons and neutrons in the nucleus of an element's atoms.
Isotope with an unstable nucleus.
The process by which atoms of a radioisotope emit energy, and/ or subatomic particles, when their nucleus spontaneously disintegrates.
Substance with a dependable component, such as a molecule labeled with radioisotope
What are the subatomic particles of atoms?
Protons, neutrons and electrons
What are the subatomic atoms that build the nucleus?
Protons and neutrons
What are the charges of the subatomic particles?
protons have a positive charge, neutrons have no charge and electrons are negatively charged.
What is an isotope?
an isotope is an atom with a different number of neutrons
What is radioactive decay?
when a radioisotope breaks down and releases radiation.
Model of electrons distribution in an atom.
Atom with an unpaired electron
Atom that carries a charge because it has an unequal number of protons and electrons.
What characteristics of the outer most shell dictates its tendency to gain or loose electrons?
they can gain a positive charge by loosing an electron or gain a negative charge by accepting an electron.
How are electrons organized around the atomic nucleus?
they are on orbitals called shells.
What is an ion?
an atom that has unequal numbers of electrons and protons.
An attractive force that arises between two atoms when their electrons interact.
Groups of two or more atoms that are joined by chemical bonds.
Molecule that has atoms of more than one element.
Chemical bond that consists of a strong mutual attraction between ions of opposite charge.
Separation of charge into positive and negative regions.
Measure of the ability of an atom to pull electrons away from other atoms.
Chemical bond in which two atoms share a pair of electrons.
in the molecule H2O the O is negatively charged and the H is positively charged the Oxygen then pulls the electrons from the Hydrogen atom towards itself
this is called a Dipole Moment.
What are the three types of Chemical bonds?
Ionic,Polar Covalent and nonpolar covalent bonds
How do we characterize each type of bond?
an ionic bond is when there is attraction between ions with opposite charges.
A Covalent bond two atoms share a pair of electrons
Hydrogen bond has attraction between a covalently bonded hydrogen atom and another atom taking part in a separate covalent bond.
Attraction between a convalent bonded hydrogen atom and another atom taking part in a separate covalent bond.
Transition of a liquid to a gas.
A measure of molecular motion- a way to measure the energy of molecular motion.
Property of a substance that arises from the tendency of its molecules to resist separating from one another.(water has this from Hydrogen bonds)
a substance that can devolve other substances. water is excellent for this because of its ability to form Hydrogen Bonds
Describes a substance that dissolves easily in water. (water loving)
Ionic compound that releases ions other than H+ and OH- when it desolves in water.
A dissolved substance.
Homogeneous mixture.(ex. salt dissolved in water,)
An intermingling of two or more types of molecules.
Describes a substance that resists dissolving in water.(water hating, ex. oils)
What is the unique characteristic of the water molecule?
it has Cohesion
What are the emergent properties of water?
Cohesion, hydration shell, and temperature
the number of molecules or ions per unit volume of solution.
A measure of the number of hydrogen ions in a fluid.
A Substance that releases Hydrogen ions in water.(lower pH)
A substance that accepts hydrogen ions in water.(raises pH)
Set of chemicals that can keep the pH of a solution stable by alternately donating and accepting ions that contribute to pH.
What is responsible for raising a pH?
What is responsible for lowering a pH?
How do we define acids and bases?
Substances that rise or lower the pH level.
What is the roll of a buffer in biological systems?
it acts as a stabilizer of the pH level.