Chem 1040 exam 1

Physical change

Affects form, not composition (melting, boiling, dissolving)

Chemicals change

New substance formed (burnin, rusting, reacting with acid)

Accuracy

Closeness to true value

Precision

Repeatability/consistency

Mass percent

% by mass = mass of element/mass of compound x 100

A

Mass number (protons + neutrons)

Z

Atomic number (protons)

X

Element symbol

Covalent bond

None-metal + Non-metal (share electrons)

Ionic bond

Metal + Non-metal (transfer electrons)

Molecular mass (molar mass)

Sum of atomic masses of all atoms in the formula

Arrangement of electromagnetic spectrum (low to high)

Radio<microwaves<infrared<visible<UV,X-rays<gamma

Diffraction

Bending around edges/slits

Refraction

Bending when entering new medium

Continuous line spectrum

All wavelengths (white light)

Line spectrum

Only certain wavelengths (atoms emitting/absorbing)

Absorption

Electron jumps to higher energy level

Emission

Electron falls back down, releases photon

Ionization energy

Energy required to remove an electron from an atom in the gas phase; increases across a period, decreases down a group

Quantum number n

Principle from 1-infinity

Quantum number l

Angular momentum: shape of the orbital (0-s, 1-p, 2-d, 3-f)

Quantum number ml

Magnetic: orientation (-l → +l)

Quantum number ms

Spin: +1/2 or -1/2

Neutral atom

Electrons=protons

Ions

• + =less electrons

• - =more electrons

Shielding

Inner electrons block outer electrons from nucleus

Penetration

How close orbital electrons get to the nucleus (s > p > d > f)

Aufbau Principle

Electrons fill lowest-energy orbitals first

Hund’s Rule

Fill orbitals singly before pairing

Pauli exclusion principle

No two electrons can have the dame four quantum numbers

Periodic trend for ionization energy

Increases across, decreases down

Periodic trend for electron affinity

More negative across, less negative down

Periodic trend for atomic radius

Decreases across, increases down

Periodic trend for electronegativity

Increases across, decreases down

Full electron configuration

1s 2s 2p 3s 3p 4s 3d 4p 5s 4d 5p 6s 4f 5d 6p 7s 5f 6d 7p

Mass conversions

1 kg=10³g

1g=10³mg

1g=10^6 micro grams

Energy conversions

1kJ=1000 J

1 eV=1.602 × 10^-19

Light equations

Speed of light (C)= 3.00 × 10^8 m/s

Planck’s constant (h)= 6.626 × 10^-34 Js

Energy of a photon (E)=2.718 hv= hc/wavelength

Angstrom (A with a circle on top)

1 × 10^-10 m

Group one

Alkali metals

Group two

Alkaline earth metals

Group three-twelve

Transition metals

Group thirteen

Boron group

Group fourteen

Carbon group

Group fifteen

Nitrogen group

Group sixteen

Oxygen group

Group seventeen

Halogens

Group eighteen

Noble gases

1 in equals ? Cm

2.54cm

1 mile equals ? Km

1.609km

1qt equals ?mL

946.4mL

1lb equals ?g

453.6g

1cc 1 cm³ = ?

1 mL