Tuesday, September 27, 2011

Scientific Notation and Matter--Chemistry 11 by Tina Zhao

Scientific Notation:
-Scientists have developed a shorter method to express very large numbers. This method is called scientific notation. Any number in scientific notation will be between 1 to 10 and multiplied by a power of 10.
E.g. write  123,000,000,000 in scientific notation
First step: Put the decimal after the first digit and drop the zeros

Second step: you look the coefficient first.In this number coefficien will be 1.23.
Third step:count the number of places from the decimal to the end of the number.and then found exponent 
Answer:
*Numbers less smaller than 1 will have a negative exponent.
*Move decimal to the left-positive exponent
                                 rigth-negative exponent.
Rules for Multiplication in Scientific Notation:
1) Multiply the coefficients
2) Add the exponents (base 10 remains)
Example 1: (3 x 104)(2x 105) = 6 x 109
Link for Scientific Notation practice :http://www.edinformatics.com/math_science/scinot_mult_div.htm
Rules for Division in Scientific Notation:
1) Divide the coefficients
2) Subtract the exponents (base 10 remains)
Example 1: (6 x 106) / (2 x 103) = 3 x 103
Link for Science Notation practice:http://www.edinformatics.com/math_science/scinot_mult_divb.htm

what is Matter?
-Anything that has Mass and Takes up space.
What is Mass?
-A property of matter that cause it to have weight. Mass measures the resitance of an object to a change in its state of motion.
Matter
1.  Mixture                                                      
-have more than one set of properties                     
-physically combined                                         
-more than one kind of substance                             
 Homogenou:i)uniform throughout.ii)appear to have only one component.*solution,colloid                
Heterogeneous:i)non uniform.ii)appear to have more than one component.*suspension,mechanical mixture.                  

2. pure substance
-one set of properties
-one kind of particle
Element:i)simplest form of matter.ii)can't be decomposed.iii)made up pf atoms.*metal,non-metal,metalloids
Compound:i)made up of element.ii)smallest particle is called molecule.
*Ionic:acid,base salt
*covalent:organic compound