protons (+)

neutrons (O charge)

electrons (-)

What three subatomic particles make up atoms?

Because they have the same number of electrons, all isotopes of an element have the same chemical properties.

How are all of the isotopes of an element similar?

Ionic and covalent  bonds.

What are the two main types of chemical bonds?

atom

The Greek word atomos, which means "unable to be cut" was first used to refer to matter by the Greek philosopher Democritus nearly 2500 years ago.

The basic unit of matter which contains protons, neutrons, & electrons.

nucleus

Strong forces bind protons and neutrons together to form the nucleus.

The center of the atom which contains the most massive subatomic particles (protons & neutrons).

electron

They are in constant motion in the space surrounding the nucleus.  

 Negatively charged particle (-) with 1/1840 the mass of a proton.

element

• More than 100 elements are known, but only about two dozen are commonly found in living organisms.

A pure substance that consists entirely of one type of atom. 

isotopes

• Atoms of the same element that differ in the number of neutrons. 

compound

A substance formed by the chemical combinations of two or more elements in definite proportions.

water= H_²O

or

table salt= NaCl 

glucose= C₆H₁₂O₆

Ionic bond

• Recall that atoms are electrically neutral because they have equal numbers of protons and electrons. An atom that loses electrons has a positive charge.  An atom that gains electrons has a negative charge.

It is formed when one or more electrons are transferred from one atom to another.

ion

+ and - charged atoms that have lost or gained electrons; form between a metal & a non-metal.

Na⁺ Cl^- 

Ca²⁺  S^-2

Covalent Bonds

• When the atoms share 2 electrons, the bond is called a single covalent bond.  Sometimes the atoms  share 4 electrons and form a double bond.  In a few cases, atoms can share 6 electrons and form a triple bond.

They form between non-metals when electrons are shared between atoms. 

Molecule

The smallest unit of most compounds.

1N₂

1O₂

1O₃

1CO

1C₆H₁₂O₆

Van Der Waals Forces

• A slight attraction that can develop between the
   oppositely charged regions of nearby molecules. 
  
  
• Named after the scientist who discovered them.
  
  
• not as strong as ionic bonds or covalent bonds

Cations

Positively charged ions that have lost 1 or more electrons.

Anions

Ionic bond

[image]

Covalent Bond

[image]

Van Der Waals Forces

20

           +2

[image]

Atomic number?

20

                             +2

[image]

Number of neutrons?

18

                        +2

[image]

Number of electrons?

18

                                     -2

[image]

Number of electrons?

32.065

                                       -2

[image]

(Relative) Atomic mass?

17

                                                   -2

[image]

Number of protons?