Chemistry: Midterm Review

What element is the most electronegative?

Fluorine

Where are protons located, what is their charge, and what is ther size?

nucleus, 1 AMU, positive

Where are neutrons located, what is their charge, and what is ther size?

nucleus, 1 AMU, neutral

Where are electrons located, what is their charge, and what is ther size?

electron cloud, 1/1836 AMU, negative

What is an isotope? What information do you need for isotope notation?

An isotope is a version of an element with a different number of neutrons. The atomic mass, and number are needed for isotope notation.

What element is the largest in group 13?

Nihonium

How many valence electrons does oxygen have? What about sulfur?

sulfur has 6 valence electrons, and so does oxygen.

What is the oxidation state of elements located in group 13?

-3

What type of metals have the greatest metallic charcter?

Alkalai metals

What is the electron configuration of Beryllium?

1s²2s² OR [He] 2s²

What is the electron configuration of Argon?

1s²2s²2p⁶3s²3p⁶ OR [Ne] 3s²3p⁶

In what two blocks does the orbital number go down by one?

D and F

Which is larger phospherous or silicon?

silicon

Which is larger zirconium or xenon?

zirconium

What are the properties of metals?

Malleable (ductile), lusterous, conducts heat/electricity.

What are the properties of nonmetals?

Dull (not lusterous), brittle, poor conductor of heat/electricity?

What are the properties of metaloids?

Semi-conductive, brittle or malleable/ductile, sometimes lusterous

Explain how light is emitted when an element (sulfur) is expposed to a flame.

A photon is emitted.

Steps…

1. atom gains energy from outside source

2. energy causes atom to jump to excited state (higher energy orbital)

3. electrons eventually leave excited state and return to a ground state (starting orbital)

4. when electrons go back to a ground state, it emits a photon (energy exits) and its wavelength (related to energy) dtermines the color of the light seen

If the flame had a measured wavelength of 5.97 × 10 ^-7 m. What is the wavelength in nm?

597 nm

Using this emission spectcra, identify the gases located in the unkown mixture.

Gases A, B, and D are in the compound. The lines of those gases match up to the unkown mixture.

What kind of waves have the highest energy, and what kind of waves have the lowest?

Gamma rays have the highest, and radio waves have the lowest

What is the visible spectrum?

Photons (only radiation humans can see)

What is the visible spectrum from highest to lowest wavelengths?

-Wavelengths from 400nm to 750nm

Red: 750-620 Lowest Energy/Longest Wavelengths

Orange: 620-590

Yellow: 590-570

Green: 570-495

Blue: 495-450

Violet: 450-400 Highest Energy/Shortest Wavelength

What is a continuous emission spectrum?

a complete visible spectrum

What is an emmision line?

colored photons emitted by a substance (unique for every atom/element)

What is an absorption line?

opposite of emmision spectra

What is an emission spectra?

Wavelengths of the photon being emitted

As frequency increases, does energy increase or decrease?

increase

As wavelength decreases, does frequency increase or decrease?

increase

As energy increases, does wavelength increase or decrease?

decrease

Who created the first periodic table, and what was it organized by?

Medeleev, organized by atomic mass

Who created the current periodic table, and what is it organized by?

Mosley, organized by atomic number (protons in an element) and metals and nonemetals.

What is metallic character?

How pronounced metallic properties are in elements

What is atomic radius?

How large the atom is (size not mass)

• distance from nucleus to outer-most orbital

What is electronegativity?

The atom’s potential to attract (gain) electrons from other atoms (How badly it wants to)

• the larger the number to more potential

• how likely the atom is going to gain electrons

What is ionization energy?

The energy required to remove an electron form an element (goes with electronegativity)

• getting rid of electrons

• for every electron lost - ionization energy increases (10 electrons = 10 energies)

• Every time you lose one, the next is harder to lose

• when there is a large increase the atom is done losing electrons

What does electron configuration show?

Shows where the electrons are in sub-orbitals if an atom (it is another layer to Bohr models)

What are the steps to drawing a L.D.S (Lewis Dot Structure)

1. Find the amount of valence electrons (don’t draw nucleus like a Bohr model)

2. Draw the chemical symbol

3. Pick 1 side first (NO CORNERS)

4. *remeber electrons hate pairing up unless it is needed (similar to seats on a bus). 4 spots (start top, go clockwise)

   KEY: DOTS=VALENCE ELECTRONS (8 max)

What is an ion?

An atom that has gained a charge due to a change in the number of electrons.(result of ionic bonds/compounds)

What is a cation, and what is its charge?

A cation has a positive charge, it is the element losing valence electrons, and it is the metal in the ionic compound

What is an anion, what is its charge?

AN anion has a negative charge, it is the element gaining valence electrons, and it is the nonmetal in the ioic compound.

What is the exponent in ionic compounds?

The oxidation state.

How do you name an ionic compound?

metals →stay the same (normal)

nonmetals →change ending to -ide

What are the properties of ionic compounds?

Combination of metal and nonmetal properties (similar to metalloids)

1. Form crystals (rough shape) (ex. table salt)

2. Brittle

3. Soluble in water (dissolves)

4. Only conduct elecctricity when dissolved in water

5. High melting/boiling points

Are covalent compounds and molecular compounds the same thing?

Yes, covalent compounds create molecules.

What kind of elements do covalent compounds consist of?

Multiple nonmetals (2+)

How are covalent bonds formed?

Overlapping valence shells.

• shared electrons (bonds)(complete valence shell)

• paired eletrons (don’t touch)

What is the prefix for one?

mono

What is the prefix for two?

di

What is the prefix for three?

tri

What is the prefix for four?

tetra

What is the prefix for five?

penta

What is the prefix for six?

hexa

What is the prefix for seven?

septa

What is the prefix for eight?

octa

What is the prefix for ten?

deca

Which element does the negative dipole go on (*hint: looks like -S)

the more electronegative one

What is VSEPR?

Valence Shell Electron Pair Repulsion

What does VESPR declare?

covalent bonds and lone pairs space out as much as possible around the central atom

• can be used to determine shape

What is electron domains?

Number of bonds + number of lone pairs

• same thing as electron group