Chemsitry exam review pt2

Dalton’s Atomic Theory

Dalton’s Atomic Theory

Law of Definite Proportions - compounds have a fixed ratio (H2O etc)

Law of Multiple Proportions - two elements can form various compounds with carious ratios (CO2 & CO etc)

Nucleus

e center of an atom with most of its mass, hosting protons and neutrons

Neutrons

uncharged particles in the center of most atoms, producing gluons which bind the nucleus together

Protons

positively charged particles in the center of atoms. Each element has a unique number of protons per atomic nucleus.

Electrons

negatively charged particles in the orbitals of atoms located on the outside of atoms. Electrons can be gained, lost, or shared through reactions.

Atomic Number

unique number for an element which indicates how many protons are in the core of its atoms

Mass Number

the sum of protons and neutrons in the core of an isotope of a given element

Isotope

a specific type of element defined by its mass number and thus its protons and neutrons. (eg carbon-12

Average Atomic Mass

the weighted average of the existing isotopes for a given element. This allows chemists to accurately measure moles, as this mass is given on the periodic table for each element

Mole

chemist’s counting units for atoms. 6.022x10^23 atoms of an element can be measured by obtaining the average atomic mass in grams.

Molar Mass

the sum of the masses of each atom in a compound’s molecular formula. Molar mass is used to measure moles using grams.

Proton charge

Positive

neutrino charge

neutral

electron charge

negative

proton mass amu

1 amu

neutron amu

1

electron amu

0 amu

proton in atom

nucleus

neutron location

nucleus

electron location

orbital

electromagnetic radiation

any form of light, visible or invisible

frequency

number of times a wave passes per second, measured in Hertz (Hz

wavelength

distance between two peaks of a wave. Visible light is measured in nanometers (400-700nm

electromagnetic spectrum

all types of light arranged in order of increasing frequency. This spectrum categorizes all types of photons.

quantum

packet or quantity of energy discovered from the Photoelectric Effect experiment

ground state

lowest electron energy state of an atom or molecule

photons

particle of light produced and absorbed via charged particle interactions

quantum theory

theory explaining the wave nature of particles, especially electrons

orbitals

regions of space around an atomic nucleus where one or two electrons may be found

J.J. Thomson

discovered the electron and made the inaccurate Plum Pudding atomic model

Ernest Rutherford

discovered the atomic nucleus via the Gold Foil Experiment

Neils Bohr

discovered atomic energy levels by calculating the hydrogen line emission spectrum

Erwin Schrodinger

developed the electron wave equation which correctly models electrons within atoms

Give four examples of electromagnetic radiation

Radio, Microwaves, IR, visible, UV, x-ray, gamma

As the frequency of a wave increases, its wavelength

decreases

As the frequency of a wave increases, its energy

increases

All electromagnetic radiation has the same ______.

Speed

Light and electrons have a dual wave-particle nature

Light travels in a line like a particle, yet can

smear across an area and interfere like a wave

When an electron gains energy by being heated or having an electrical current applied, it jumps to a

______________ energy level

higher, excited

As it falls back, it gives off a _________ of light with a specific

frequency

photon

This is why elements have unique _________________ spectrums

atomic emission

unique

_______________ colors

pattern/distribution of

Which of the following indicates the s sublevel in the third main energy level

3s

A spherical electron cloud surrounding an atomic nucleus would best represent _____

an s orbital

Orbital maximum of numbers

2

An orbital that would never exist in the quantum description of an atom is

3f

The noble gases are alike in that they all

c. are rather unreactive

In the modern periodic table, elements are ordered

c. according to increasing atomic number

The periodic law states that

the physical and chemical properties of the elements form a pattern when arranged by

increasing atomic number

The most distinctive property of the noble gases is that they are

mostly inert

Elements in the same row on the periodic table are said to be in the same

Family/group

Elements in the same group have similar properties because they have the same number of

Valence electrons

elements with similar properties appear at regular

intervals (falling within the same group) when they are arranged in order of increasing atomic number.

Periodic law

All of the group 18 elements besides helium are

A and b

Most reactive groups

1 and 17

In general, the atomic radii of the main-group elements _____________________ down a group

Increase

The atomic radii of group 3 elements are generally _____________________ than the atomic radii of

group 6 elements

larger

Smallest atomic radius Na, Li, K, Fr

Li

Smallest atomic radius Hf, Cs, Pb, Pt

Pt

In general, ionization energies of the main-group elements _____________________ across each

period

increase

Among main-group elements, ionization energies generally _____________________ down each

group.

decrease