## 1. In 1808, the basis of our current atomic theory was developed by?

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1. In 1808, the basis of our current atomic theory was developed by?

JohnDalton’s

1. Atoms have been found to be made up of particles called

1. Electrons

2. Protons

3. Neutrons

1. Two particles in (2 above ) can be found in the

Nucleus

1. Show the electrical charges for each of the particles

1. Electrons- negative charge

2. Protons- positive charge

3. Neutrons- neutral (no charge)

1. Explain how these particles relate to the atomic number and the mass number of an element. Protons in an atom gives the element its atomic number

Thetotal sum of protons and neutrons gives the Mass number of anelement.

1. Explain how an element can have one or more isotopes. If there exists atoms with an equal number of protons but different number neutrons, then they are isotopes of the element.

1. Indium (In) has two naturally isotopes. In-113 has a mass of 112.9 a.m.u and an abundance of 4.30%. In-115 has a mass of 114.9 a.m.u and an abundance of 95.70%. Using the weighted average mass method, calculate the atomic mass of Indium. (Show all your work.)

Convertingthe percentages to decimal

4.30%= 4.30/100

=0.043for In-113

95.70%= 95.7/100

=0.957 for In-115

Weightedaverage mass of Indium = (abundance of In-113 in decimal × mass ofIn-113) + (abundance of In-115 indecimal × mass of In-115)

=(0.043 × 112.9) + (0.957 × 114.9)

=4.8547 + 109.9593

=114.814

=114.8 (to four significant figures)

1. What are the periods of the periodic table list them numerically?

Thehorizontal rows of elements, which have the same number of energyshell.

Theyinclude Period 1, 2, 3,4,5,6, and 7.

1. What are the Groups of the periodic table, list their names (if any), and list their Group designations.

Groupsare the vertical columns in the table

GroupI- Alkali metals

GroupII- Alkaline earth metals

GroupIII

GroupIV

GroupV

GroupVI

GroupVII-Halogens

GroupVIII- Noble gas

1. Where can the metals be found on the Periodic Table?

Allelements found on the left hand side of group three elements exceptBoron and Hydrogen and going down along the group in a stair wayexcluding Germanium and Antimony are metals

1. Explain what a metalloid is and provide the chemical symbols for the known metalloids.

Theyare elements with both properties of metals and nonmetals. Thechemical symbols of known metalloids are: B, Si, Ge, As, Sb, Te

1. What is an electromagnetic spectrum? It is a term used to describe the electromagnetic waves arranged in order of their wavelengths and frequencies

1. What is the wavelength of visible light in the Electromagnetic spectrum? 400nm-700nm

1. Show the wave equation in symbols and by names.

V=λf

Speed=wavelengthx frequency

1. Define a photon and give two examples of how they are used. It is a particle of light that has both energy and momentum. It is employed in a photographic film to convert silver iodide to iodine and silver. Photons are also used during photosynthesis

1. In an atom, the electron are located in various

orbitals

1. What is a sub-level and what are the four classes?

Itis where electrons are found within each energy level

Thefour classes of energy level are s, p, d &amp f

1. How many electrons can be located in each of the four classes of sublevels?

Scan accommodate a maximum of 2 electrons

Pholds a maximum of 6 electrons

dholds a maximum of 10 electrons

Fholds a maximum of 14 electrons

1. In what order is each sublevel filled?

Theenergy sub-level close to the nucleus is filled with electrons firstand once it is filled the next energy sub-level is filled. Thisprocess continuesforall the available electrons

1. List three primary rules an atom’s electrons follow in filling the orbital of its grounds state.

a)Aufbauprinciple

b)Hund’s rule

c) Pauli Exclusion Principle

1. Why can’t there be more than two electrons in a sub-level?

Electronspossess magnetic fields with north-south possible orientations.Therefore Electrons can reside in one orbital if their orientationsare mutually opposed.

1. Orbital are arranged from 1st to 4th. Energy levels

4d105s25p2

1. The third energy level has 2S orbitals,6p orbitals, and 10 d orbitals

1. The fourth energy level can hold 32 Electrons, and there are 16 orbitals to accommodate them

1. Explain how the elements’ electron configuration affect the way the periodic table is arranged.

Elementswith which the electrons number in the outermost energy shell isequal belongs to one group. All elements in a given period havesimilar energy shells

.

1. Explain how the electrons in their ground state differ from those in an excited state.

Foran electron to be in an excited state, it must absorb energyequivalent to the energy difference of the two states’ difference.

1. When an excited electron returns to its ground state it

Releasesthe excess energy as a photon which is seen as visible light inemission spectrum

1. Explain the octet rule in terms of electron orbital’s. Atoms tend to lose or gain electrons so as to have electrons in the outer most energy level equal to that of its nearest noble gas.

1. Explain the lack of reactivity of the noble gasses regarding their electron orbitals

Theyhave fully filled electron orbital shells that cannot hold any otherelectrons

1. What is a valence electron

Itis the electron in the outer shell of an atom which, can betransferred or shared during bonding.

1. What does Lewis symbol represent?

itrepresents the electrons in the valence shell of an atom or ionplaced around the element’s letter symbol by dots

1. Provide Lewis symbol for K, Al, As, Cs, Ba, C, O, Xe, and I.

1. How does atomic size change from top to bottom and from left to right of the Periodic Table?

Asone moves down the group the atomic size rises and from left to rightand the atomic size decreases

1. How does the ionization energy change from top to bottom and from left to right of the Periodic Table? Increases as you move from left to right and decreases down the group

2. Explain the difference between elements and an ion of an element. An element the simplest form of substance that cannot be made into simpler substances chemically while an ion is an atom that has lost or gained an electron

3. Why do elements want to bond? Elements bond so as to attain noble gas electron configuration

4. Chemical l bonds involve the sharing or transfer of electrons

5. A cation is a positive ion

6. An anion is a negative ion

7. What do you need to be careful of when writing formulae for ionic bonded compounds? Arrangement of the elements and the valences of the elements

8. Write the formulae for the followings compounds

1. Barium fluoride – BaF2

2. Potassium Oxide- K2O

3. Sodium carbide –Na2C2

4. Francium bromide –FrBr

5. Copper II oxide – CuO

6. Calcium hydride- CaH2

1. Why do group 1A and 1B elements bond so easily with group 7A elements?

Group1A and 1B elements want to lose 1 electron to attain the noble gaselectron configuration on the other hand group 7A are ‘hungry’for one electron to become stable in the outermost energy shell hencethey bond easily

1. Explain the mechanism involved in forming an ionic bond. An ionic bond is formed when an electron moves from metallic element to nonmetallic element. When an element loses an electron, it becomes positively charged, and if it gains electrons it becomes positively charged. In an ionic bond, the two oppositely charged ions are held together by electrostatic attraction.

2. Which types of bonds are most prevalent in nature?

Ionic

Covalent

1. Non-polar covalent bonds share electrons true

2. An example of a molecule with non-polar covalent bonds is Hydrogen molecule

3. polar covalent bonds share electrons Yes

4. An example of a molecule with polar covalent bonds Water molecule

5. Coordinate covalent bonds share electrons true

6. Polyatomic ions usually have a) covalent bonds, but form ionic bonds with other ions.

7. Write formulae for

1. Beryllium chlorite Be(ClO3)2

2. Lithium carbonateLi2CO3

3. Potassium tartrate – K2C4H4O6

4. Ammonium phosphate – (NH4)3 PO4

5. Nickel II thiocyanate – Ni(SCN)2

6. Zinc hexacyanoferrate Zn2[Fe(CN)6]&nbsp
1. Substances with ionic bonds can conduct electricity when molten Or dissolved in water

2. Elements with metallic bonds can conduct electricity because they have free electrons

3. The high concentration of positive charge in a hydrogen bond causes the more denser substance to form.

4. What are dipoles? They are molecules that posses different charges at their end

1. A ‘’sea’’ of electrons describes the valence electrons of metallic elements

2. In the space below, draw and fully label a cross-sectional view of a quantum-mechanical

Modelof the atom. Show where the protons, neutrons, electrons, and nucleusare located

orbitals where electrons are found

Nucleuswhere protons and

N

e e e

P &amp N

N

eutronsare found

Electrons

Protonsand Neutrons Nucleus