Chapter 1

What are the 10 naturally occuring atoms that is bonded with more than one atom.

O2

O3

N2

H2

F2

Cl2

Br2

I2

S8

P4

Element
 one of a class of substances that cannot be separated into simpler substances bychemical means. See also chart under periodic table.
compound?
composed of two or more parts, elements, or ingredients: Soap is a compound substance
Homogeneous Mixture

 

  

any combination of substances that has uniform composition and properties; 

a mixturethat is uniform throughout

 

Heterogenous Mixture

  any combination of substances that does not have uniform composition and properties;a mixture of physically distinct substances with different properties

Physical change vs chemical change
The difference between a physical reaction and a chemical reaction is composition. In a chemical reaction, there is a change in the composition of the substances in question; in a physical change there is a difference in the appearance, smell, or simple display of a sample of matter without a change in composition. Although we call them physical “reactions,” no reaction is actually occurring. In order for a reaction to take place, there must be a change in the elemental composition of the substance in question. Thus, we shall simply refer to physical “reactions” as physical changes from now on. 

Atom,Molecule,hydrate

 

give examples and tell difference

an atom is the simplist form (S)

molecule is made up of atoms.(H2O)

a hydrate has water in it.(H2O2)

Daltons Atomic Theory
All matter is made up of tiny submicroscopic things known as atoms.
The Law of definite proportions

ohn Dalton (1803) stated this law as ‘when two elements combine with each other to form two or more than two compounds, the massof the element which combine with the fixed mass of the other bears a simple whole number ratio’.

 

Example  

 

Carbon monoxide (CO): 12 parts by mass of carbon combines with 16 parts by mass of oxygen.

how many atoms?

 

2H2Cl5+6O2C2

38 with margin of error +-1
Decomposition
when one substance is changed into two or more through a checmical reaction.
example of Pure Substances
Elements and compounds are pure substances
Solution
Homogeneous Mixtures are solutions
Phases
In a heterogenous mixture the different”layers” that is created.

Scanning Tunneling Microscope

 

A instrument that allows people to map the surface of a solid with great detail.
Free Element
a element that is not combined with another element in a compound