Chemistry of Life
Card Set Information
Chemistry of Life
biology chemistry Life
1st tri honors Biology 2nd test
what are all substances made out of?
a substance that can't be broken down into simpler substances
On earth, how many elements occur naturally?
how many elements are essentail to living organisms?
what four elements make up more than 96% of the mass of a human?
carbon, hydrogen, oxygen, and nitrogen
Each element is abbreviated by a one or two letter ________.
the smallest particle of an element that has the characteristics of that element
what is at the center of an atom?
what is the nucleus made up of?
charged particles called protons and paricles called neutons, which have to charge
All Nuclei are _______ charged because of the presence of ______.
what forms a cloud around the necleus?
Are they positive or negative?
electrons energy levels
Define: energy levels
where electrons travel around necleua in certain regions
What is the formula that is used to figure out how many electrons an energy level can hold?
N= the energy level
Atoms contain __________ numbers of electrons and protons. Therefore, they have____ ________.
atoms of the same element that have different numbers of neutrons in the nucleus
a substance that tis composed of atoms of different elements chemically combined.
Why to atoms combine with other atoms?
to become be stable
How to atoms become more stable by combining?
by sharing electrons
Define: covalent bond
when two atoms share electons, covalent bond is the force that holds them together
a group of atoms held together by covalent bonds and having no overall chrage.
What two types of thing are bonding in a covalent bond?
a nonmetal to a nonmetal
an atom that gains or loses electrons that has an electrical charge
Define: ionic bond
a bond formed by the mutual attraction of two ions of opposite charge.
What two types of thing are bonding in an ionic bond?
a metal to a nonmetal
Ionic bonds do not form _____ _______.
a combination of substance that don't combine chemically but retain ther individual properties
a mixture in which one or more substances are distributed evenly in another substance
water make up ___ to ____ percent of most organisms.
70 to 95
Define: polar molecule
a molecule with an uneaqual sidtribution of charge
water is _____.
a polar molecule
total of all chemical reactions that occur within a living organism
substances that under-go chemical reactions
substances formed by chemical reactions
What is the easiest way to understand chemical reacctions?
atoms are never created or destroyed, they are simply rearranged.
Chemical equations must always be written so that they are _______.
What are the five unique properties of water?
High Heat Capicity
High Boiling and High Freezing Points
high surface tenison
expands when frozen
a symbol to describe how acidic or basic a solution is; the pH scale ranges from 0 to 14; a solution with a pH of 7 is neutral, above 7 is basic, and below is acidic
a substance that forms hydroxide ions in water; solutions with a pH of 7 or above
any substance that forms hydrogen ions in water; acidic solutions have pH below 7
What is a family on the periodic table?
What is a Period on the periodic table?
I'm a ______ based life form
Why is Carbon the best?
It has four open bonding sites
carbon filter the best because it is so tightly bonded