Atoms and Molecules,

carbohydrates

"Compound containing carbon, hydrogen, and oxygen in the approximate ratio of 1:2:1 CH2O (e.g., sugars, starches, and cellulose)"

electron shell

(2,8,18) the orbital where electrons are located, outside of the nucleus. The shells contain different energy levels.

mixture

(chemistry) a substance consisting of two or more substances mixed together (not in fixed proportions and not with chemical bonding)

criteria for life

1) contain DNA, 2) can convert energy in their surroundings into energy that can sustain them, 3) can sense and respond to changes in their surroundings, 4) reproduce

covalent bond

A chemical bond that involves sharing a pair of electrons between atoms in a molecule

chemical formula

A combination of symbols that represents the elements in a molecule or compound and their proportions (H2O).

organs

A combination of tissues designed to perform a specific function or several functions

what makes an atom stable?

A full outer layer of valence electrons

molecule

A group of atoms held together by covalent bonds.

surface tension

A measure of how difficult it is to stretch or break the surface of a liquid. Water has a high surface tension because of the hydrogen bonding of surface molecules.

diatomic

A molecule consisting of two atoms

Anion

A negatively charged ion An atom that gained electrons and therefore has a negative charge. Nonmetals gain electrons

electron

A negatively charged particle that orbits the nucleus of an atom.

Cation

A positively charged ion An atom that lost electrons and therefore has a positive charge. Metals lose electrons

proton

A positively charged subatomic particle found in the nucleus of an atom

element

A pure substance that cannot be broken down into other substances by chemical or physical means

neutron

A subatomic particle of about the same mass as a proton but without an electric charge, present in all atomic nuclei except those of ordinary hydrogen.

compound

A substance made up of atoms of two or more different elements joined by chemical bonds

polar bonds

A type of covalent bond between two atoms in which electrons are shared unequally.

non polar bonds

A type of very strong bond, a covalent bond where atoms are shared equally

ion

An atom or group of atoms that has gained or lost one or more electrons, thus acquiring a charge.

isotope

An atom that has the same number of protons as other atoms of the same element do but that has a different number of neutrons

chemical bonds

An attraction between two atoms resulting from a sharing of outer-shell electrons or the presence of opposite charges on the atoms. The bonded atoms gain complete outer electron shells.

matter

Anything that takes up space and has mass

disaccharides

Carbohydrates that are made up of two monosaccharides: sucrose, lactose, maltose

monosaccharides

Carbohydrates that are simple sugars: glucose, fructose, galactose. rapidly absorbed and readily distributed

tissues

Groups of cells with a common structure and function.

liquid

In this state of matter the molecules are loosely linked. They move more slowly. As it gets warmer they spread out. If it cools they get closer together. This state of matter takes the shape of its container.

gas

In this state of matter the molecules are spread out and they move fast. The warmer it is the more the more the molecules spread out and the faster they move. As it cools the molecules come closer together and tend to slow down. This state of matter disperses into the space that it is in.

solid

In this state of matter the particles are tightly linked together. They vibrate. The colder it gets the closer together the molecules get and the less they vibrate. This state of matter holds its own shape.

ionic bonds form when_______

One atom transfers an electron to another atom

hydrogen bonds (attraction)

Relies on attraction of (-) side of one molecule, with the (+) side of another molecule

atom

Smallest unit of matter that retains the properties of an element

electron cloud

The area around the nucleus of an atom where the atom's electrons are most likely to be found.

atomic mass

The average mass of the atoms of an element (protons and neutrons). Typically found at the bottom of the element square (ex: Carbon has an atomic mass of 12.01).

cells

The basic unit of structure and function in all living things

atomic nucleus

The central part of an atom that contains both protons and neutrons.

valence electrons

The electrons in the outermost shell (main energy level) of an atom; these are the electrons involved in forming bonds.

atomic number

The number of protons in the nucleus of an atom; this determines the atoms name and place in the Periodic Table.

ionic bond

a chemical bond in which one atom loses an electron to form a positive ion and the other atom gains to electron to form a negative ion

polar covalent

a covalent bond between atoms in which the electrons are shared unequally

organism

a living thing that has (or can develop) the ability to act or function independently

inert atom

an atom with a complete valence shell is stable and unreactive

sucrose

glucose + fructose

lactose

glucose + galactose

maltose

glucose + glucose

organ systems

groups of organs that work together to perform a necessary life function

one atom bonding to another is called__________

ionic bond

organelles

metabolic machinery of a cell, A tiny cell structure that carries out a specific function within the cell.

organic molecules

molecules containing carbon and hydrogen, have covalent bonds

Atomic mass - atomic number =________

number of neutrons

what determines the characteristics of an element

the number of protons