Unit 1- Molecules & Compounds Flashcards Preview

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Flashcards in Unit 1- Molecules & Compounds Deck (13):
1

Intermolecular force

Forces between molecules that hold molecules ex: hydrogen bonding, dipole dipole, London dispersion force

2

Intramolecular force

Any force that holds together the atoms making up a molecule or compound. Ex: ionic bond, metallic bond, covalent bond

3

Dipole dipole force

-2 dipolar molecules interact
-opposite poles attract
-molecules hold together
To classify
-ionic or polar covalent bonds
AND
unsymmetrical shape

4

Van der Waals force

Attractive and repulsive
Weak
Comes from dipoles (2 charges)
Dipole dipole and London dispersion force

5

London dispersion force

Weakest
Temporary dipoles form (1 side + the other -)
Between non-polar molecules
To classify
-non-polar covalent bonds
OR
-symmetrical shape for polar covalent or ionic bonds

6

Valence electrons

The electrons in the outermost shell
the electrons on an atom that can be gained or lost in a chemical reaction

7

Molecules

A molecule is the smallest particle in a chemical element or compound that has the chemical properties of that element or compound. Molecules are made up of atoms that are held together by chemical bonds. These bonds form as a result of the sharing or exchange of electrons among atoms.

8

Compounds

a substance that results from a combination of two or more different chemical element s, in such a way that the atom s of the different elements are held together by chemical bonds that are difficult to break. These bonds form as a result of the sharing or exchange of electron s among the atoms.

9

Covalent bonds

the sharing of electrons between atoms. This type of bonding occurs between two atoms of the same element or of elements close to each other in the periodic table. This bonding occurs primarily between nonmetals
If atoms have similar electronegativities covalent bonds are most likely to occur.

10

Ionic bonds

is the complete transfer of valence electron(s) between atoms. It is a type of chemical bond that generates two oppositely charged ions. In ionic bonds, the metal loses electrons to become a positively charged cation, whereas the nonmetal accepts those electrons to become a negatively charged anion. Ionic bonds require an electron donor, often a metal, and an electron acceptor, a nonmetal.

11

Atoms

Atoms are the basic units of matter and the defining structure of elements.

12

Ions

any atom or group of atoms that bears one or more positive or negative electrical charges. Positively charged ions are called cations; negatively charged ions, anions. Ions are formed by the addition of electrons to, or the removal of electrons from, neutral atoms or molecules or other ions

13

Elements

a substance whose atoms all have the same number of protons: another way of saying this is that all of a particular element's atoms have the same atomic number.
Although an element’s atoms must all have the same number of protons, they can have different numbers of neutrons and hence different masses. When atoms of the same element have different numbers of neutrons, they are called isotopes.