Chem1010

Centi

1-100

milli

1-1000

kilo

1000-1

Scientific Notation

6.02 × 10²³

digits 1-9 (significant figures)

always significant

Leading zeros

Never significant

Captive zeros

always significant

Trailing zeros

if no decimal point-not significant

if there is a decimals point-are significant

1.457+83.2

84.7

Addition and subtraction (significant figures)

round the answer to the least number of decimal places

Multiplication and division (significant figures)

Round the answer to the least number of significant figures

4.36×0.00013

0.00057

12.300/0.0230

535

0.0367-0.004322

0.0324

Convert 1.53 g to cg

153 cg

find the area of a 5 in² square in cm². There are 2.54 cm in 1 in. this is a squared or cubed unit problem

30 cm²

5.6 m/s to miles/hour. There are 1.609 Kim in a mile. This is a compound unit problem

13 miles/hour

Density equation

mass/volume

Mass equation

density x volume

Volume equation

mass/density

What is the density of an object with a mass of 55 g and a volume of 78 ml

0.71 g/ml

What is the volume of an object with a mass of 32 g and a density of 8.3 g/ml

3.9 ml

You measure the mass of an unknown substance to be 43.895 g. Then, you take the object and drop it in 60.2 ml of water. The water level rises to 67.9 ml. What is the density of the object?

5.7g/ml

Electron relative mass, charge, and location

1/2000 amu, -1. outside the nucleus

Proton relative mass, charge, and location

1 amu, +1, inside the nucleus

Neutron relative mass,charge, and location

1 amu, 0, inside the nucleus

atomic number-on the periodic table? and definition

Yes (top #), number of protons/ identifies element

Mass number-on the periodic table? and definition

No, number of protons/the number of neutrons

Atomic mass-on the periodic table? and definition

Yes (bottom #), average of different mass #s

How do you find protons?

the atomic # (top number on periodic table)

How do you find electrons in a neutral atom?

The # electrons= the # of protons

How do you find electrons in a positive ion?

Electrons are lost: subtract charge from atomic #

How do you find electrons in a negative ion?

Electrons are gained: add charge to atomic #

How to find neutrons?

neutrons = mass# + atomic #

How many protons, neutrons, and electrons are in an atom of 48Ti

jkdjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjj22

P=22

N:48-22=26

E:22

Atomic mass vs Mass number

Atomic mass Mass number

decimal # whole #

on periodic table not on periodic table

weighted average protons and neutrons

Molar mass definition

Mass of one mole of a substance is equal to the bottom number on the periodic table

Find the molar mass of H

1.01 g

1 mol

Find the molar mass of Pb

207.20g

1 mol

Find the molar mass of NaCl

22.99+35.45=58.44g

Find the molar mass of CaCl2

40.08+2(35.45)=110.98g

I have 2 moles of H20. How many grams is this?

2 mol H20———18.02g H20= 36.04 g H20

…………………..1 Mol H20

If you have 4.25 × 10²5 molecules of HCN, how many grams do you have?

1910 g

Step 1 of photon emission

electron starts in ground state

step 2 of photon emission

Electron absorbes energy

Step 3 of photon emission

electron moves to excited state

Step 4 of photon emission

Electron releases energy in the form of a photon

Step 5 of fhe photon emission

Electron ends in ground state

Alpha particle: Greek symbol, nuclear symbol, mass, charge, penetrating power, ionizing power, and what its blocked by

4 ,4, 4 amu , +2, low, high, paper and skin

e He

2 2

Beta minus (beta):Greek symbol, nuclear symbol, mass, charge, penetrating power, ionizing power, and what its blocked by

0, 0, 1/2000 amu, -1, medium, medium, aluminium and wood

B e

-1 -1

Beta plus (positron): Greek symbol, nuclear symbol, mass, charge, penetrating power, ionizing power, and what its blocked by

0, 0, 1/2000 amu, +1, medium, medium, aluminum and wood

B e

+1 +1

Gamma:Greek symbol, nuclear symbol, mass, charge, penetrating power, ionizing power, and what its blocked by

0, 0,0, high, low, lead and concrete

g

0

alpha equation using 238

• - - - - - - - - — - -U

• - - - - - - - - - - - -92

238U92-4He2+234Th90