Bonds

BondsBy Regina López and Andrea Herrera

What is a bond?A bond is when two or more atoms are joined together to reach chemical stability.

What are molecules?

A molecule is a combination of two or more atoms.

What is a substance?

Substance = matter

Pure substancesElements: Na, C, K, N, Ne.

Compounds: H2O, O2, CH4, C2H6

Not Pure Substances

Homogeneous: salt water, gatorade, pepto bismol, coffee.

Heterogeneous: pozole, Chapala lake, salad, milk and cereal.

What is a compound?

A compound is any substance formed when two or more elements are bonded.

Covalent BondsA covalent bond is formed between two nonmetals.

In a covalent bond the electrons are shared.

Covalent BondsCovalent bonds include diatomic molecules of some gases.

IonWhen an atom gets a charge by either loosing or gaining electrons.

If it looses electrons it will become a positive ion and if it gains it will become a negative ion.

Ionic BondsIonic bonds are formed between one metal and one nonmetal.

In ionic bonds there is a gain and loss of electrons(The metal looses and the nonmetal gains).

Debatable if they are stronger

Ionic bonds

Polyatomic ionsA polyatomic ion is a bond between two or more atoms with a charge.

They are formed by a covalent bond and it can make ionic bonds.

Polyatomic ionsIn a polyatomic ion the resulting number of electrons and protons is not equal, an ion with two or more atoms is formed.

Common polyatomic ions

ProtonsIf the atom has more protons than electrons it means that the atom will become a positive ion.

ElectronsIf the atom has more electrons than protons it means that it is a negative ion.

Valence electronsThe valence electrons are the electrons in the outermost layer of the atom.

They determine the element´s behavior.

They are either shared or exchanged.

Valence Electrons

Valence electronsMetals usually loose their valence electrons and nonmetals usually gain them in ionic bonds.

Periodic TableThe periodic table has groups and periods.

PeriodsThere are 7 periods and they run horizontally.

GroupsThere are 8 groups (not counting the middle section that has weird-acting metals) and they are vertical.

The group number tells you the number of valence electrons.

Reactivity

Electronegativity