chem 2nd 9wks test

8/13/2019 Chem 2nd 9wks Test

1/4

Chemistry 2nd Nine Weeks Test

Calculating the number of subatomic particles in an atom or an ion

atomic number: protons and electrons

atomic mass-atomic number=number of neutrons

Define an isotope

an atom that has the same number of protons (or the same atomic number) as other

atoms of the same element do but that has a different number of neutrons (and thus adifferent atomic mass)

Write an isotopic symbol for an element

use the abbreviation on the periodic table and the number to the left on top is its

atomic mass and the number on the bottom is its atomic number

Calculate the average atomic mass for an element

Average Atomic Mass Worksheet Percent abundance x mass added to all the others

Calculate the binding energy and mass defect

Mass defect - find mass of protons and neutrons (by multiplying the amount times their

masses and add them) and then find the difference between that and the given mass

Binding energy - take the mass defect and convert it to kg (1.6605x10 -27kg/amu) and

then take this number and use the equation E=mc2(basically multiply it by speed oflight squared m/s2)

This will give you an energy which is in J/nucleus

Label a diagram of a waveRead the electromagnetic diagram

ALLTRAVEL

AT SPEED OF LIGHT

Calculate the energy, wavelength,or frequency

Energy: E=hv (h=6.626x10-34J/Hz)


2/4

Wavelength ( measured in m or nm )

Frequency (V measured Hz)

C= v (C is the speed of light or 3.00x10 8m/s)

Compare and contrast the 5 models of the atom

1. Dalton - believed atoms were indivisible (5 part theory); didnt know particles hadcharges; thought atoms were shaped according to properties

2. Thomson - cathode rays determine that electrons are negatively charged3. Rutherford - Gold foil experiment which determined that the nucleus is positively

charged - most of an atom is empty space but there is a nucleus4. Bohr - electrons orbit the nucleus in circles5. Quantum - the electrons are just zooming around not it perfect circles; orbitals

Write anuclear equation

Alpha decay

Beta decay

Positron Emission

Electron capture 0/-1 e

Gamma Decay


3/4

Nucleon - a proton or neutron Nuclide - isotopic symbol (C-14)

Compare and Contrast the different types of radiation based upon the penetratingpower of the radiation

Alpha rays are weakest (cant go through skin), then beta (can go through skin but not

bones, use for X-rays; cant go through lead), then gamma (can go through skin andbones/Everything)

Determine which elements are radioactive or stable based upon the band ofstability

Use neutron-proton ratio: 1-1.5 is considered stable

Any element above 83 on periodic table is ALWAYS

radioactive/unstable

Calculate the half-life

where AOis the initial amount and AEis the amount remaining

t=elapsed time

t1/2= duration of a half-life

or to the nth power where n is the number of half lives

Complete calculations using the mole

1 mole=6.022x1023 formula units (ionic compounds) or atoms (molecular compounds) ionic compounds involve metals and nonmetals; molecular compounds involve just

nonmetals

1 mole= molar mass (average atomic mass)

1 mole=22.4 L

molecule is the compound as a whole but atoms are individual elements; formula units

are a whole and ions make it up


4/4

Determine the percent composition

Mass/Total mass of the compound x 100

the part over the whole

Calculate molar mass

multiply how many atoms there are times its mass (C6H12O6) would be(6x12.01)+(1.100x12)+(16.00x6)

Write electron configurations and draw orbital diagrams

n = cloud size or what floor its on

l = which orbital its on (0-s, 1-p, 2-d, 3-f)

ml = is the number where it is on the orbital (l)

ms = +1/2 or -1/2 depending on the spin

orbital notation: valence electrons

Aufbau Principle: an electron occupies the loest-energ! orbital that can receive it"

s#p#d#f#g#h#i

Pauli $%clusion Principle: no to electrons can have the same set of &uantum

numbers because of opposite spins

'und(s ule: orbitals of e&ual energ! are each occupied b! one electron before an!

orbital is occupied b! a second electron

*ouis ot iagram: shos its valence electrons either at ground or e%cited state

chem 2nd 9wks test

Documents