Atomic Structure and Bonding

Question 1

First ionization energy meaning, second ionization energy meaning

Answer 1

First ionization energy- energy required to remove one electron from -each atom- in one mole of gaseous atoms to form one mole of gaseous 1+ ions.
Second ionization energy- … -Each ion-… 2+ ions

Question 2

Find the first ionization energy for chlorine and magnesium. And the second, and third ionization energy for chloride and magnesium ions

Answer 2

1st) Cl(g) -> Cl+(g) + e-
2nd) Cl+(g) -> Cl 2+ (g) + e-
3rd) Cl 2+(g) -> Cl 3+ (g) + e-

1st) Mg(g) -> Mg+(g) + e-
2nd) Mg+(g) -> Mg 2+(g) + e-
3rd) Mg 2+(g) -> Mg 3+(g) + e-

Question 3

Factors affecting ionization energy (3)

Answer 3

Atomic radius- greater radius, smaller nuclear attraction, less ionization energy.
Nuclear charge- greater nuclear charge, greater number of protons, greater attractive force on electrons, more ionization energy.
Electron shielding - more inner shells, greater shielding, less ionisation energy.

Question 4

The three orbitals
What are the orbitals represent?

Answer 4

S orbital
Px orbital
Py orbital
Pz orbital
YOU SHOULD KNOW HOW TO DRAW THEM
They represent wave patterns electrons make because electrons act like waves

Question 5

Energy levels and its equation?

Answer 5

2, 8, 18, 32
2(n^2)
Energy levels represent the number of electrons from each energy level, such as the third energy level containing 3s, 3p, 3D equals to 2 + 6 + 10 = 18 electrons

Question 6

Aufbau principal and hund’s rule

Answer 6

Aufbau principal- electrons enter lowest available energy level.
Hund’s rule- when in orbitals of equal energy electrons will try to remain unpaired ‘bus rule’

Question 7

Types of subshells

Answer 7

S
P
D
F

Question 8

Metallic bonding across the group such as from sodium to magnesium- melting point

Answer 8

The strength of metallic bond becomes stronger as each atom donates more electrons to the electron cloud such as sodium donating one electron while magnesium atoms donating two electrons, this creates a greater electron density so ions are held more tightly and strongly, more energy is then required to overcome which increases the melting point

Question 9

Strength of metallic bonding down the group such as from sodium to potassium and how this affects melting point?

Answer 9

The strength of metallic bonds becomes weaker as ions become bigger and they are more shells, therefore, ionic radius increases so the electron cloud has a bigger volume to cover, so less energy is required to overcome the attraction, so melting point decreases

Question 10

An ionization table how do you tell which element is from which group?

Answer 10

If the ionization energy increases drastically from different groups in a table that shows which group the element is from

Question 11

Where on the periodic table does element have the highest ionization energy?

Answer 11

The element to the top and most right has the highest ionization energy so it would be helium, wow! The element with the lowest ionization energy would be the element on the lowest and leftist part of the periodic table, so it would be francium

Question 12

What are two transitional metals that have exceptions to the electronic configuration? And what are their electron configurations?

Answer 12

Chromium and copper
Chromium is 1s2 2s2 2P6 3s2 3p6 4s1 3d5. The second electron in 4s goes to 3D.
Copper is 1s2 2s2 2pd 3s2 3p6 4s1 3D10.
Advice: if the electron in 3D subshell reaches four or nine they would want to be 5 and 10. So takeaway 1 electron from 4S subshell to add to 3D.

Question 13

Definition of a covalent bond

Answer 13

Strong electrostatic attraction between a shared pair of electrons and the nuclei of the bonded atoms

Question 14

What is the orbital theory in covalent bonds?

Answer 14

When a covalent bond is formed, it shares electrons and orbitals overlap. The greater the overlap the stronger the bond

Question 15

Solubility of simple covalent molecules

Answer 15

More soluble in organic solvents such as alcohol, carboxylic acid etc, than in water, some are hydrolyzed

Question 16

What is the octet rule?? And what are the exceptions to it?

Answer 16

The octet rule says atoms tend to have 8 electron in the outer shell after bonding like a noble gas, however, their exceptions of some elements may have less than eight electrons and others have more than eight electrons.

Question 17

What is it called when atoms do not have enough electrons to complete the octet? What is it called when atoms have extra electrons? What are examples of both?

Answer 17

Atoms that cannot complete the octet because they don’t have enough electrons available are called electron deficient species. One example is boron trifluoride with boron having six electrons. Atoms that have more than eight electrons are called expanded octet, this happens when atoms are in. 3 or below. One example is sulphur hexafluoride, with sulphur having 12 electrons.

Question 18

What is a dative covalent bond and what is required to form a dative covalent bond?

Answer 18

A date of covalent bond is a type of covalent bond where both electrons in the shared pair come from the same atom. One example is ammonia where nitrogen has a lone pair of electrons that are not shared with hydrogen, the lone pair of electrons are slightly negatively charged which can attract a positive hydrogen. Hydrogen will not show electrons but will be attracted to the lone pair creating ammonium which is NH4+.

Question 19

What is valence shell electron pair repulsion theory and what two things does it assume?

Answer 19

model used to predict the 3D shape of molecules by assuming:
-electrons repel as far as possible
-lone pairs repel more than bonding pairs

Question 20

Difference between bonding pairs and lone pairs, which one which one repels more strongly? List the order

Answer 20

Bonding pairs- (covalent bond) electrons shared between the atoms lone pairs- electrons are not shared, belonging to one atom only
Lone pairs repel more strongly than bonded pairs
Lone lone> lone shared> shared shared

Question 21

What are the different arrows when drawing molecules 3D?

Answer 21

The straight line represents the plane or the paper, the triangle filled in represents out the paper and towards me and the marked dotted triangle represents a away from me and into the paper

Question 22

What is another word for dative covalent bonds?

Answer 22

Coordinate bonds

Question 23

What is a electronegativity? What is the definition of electronegativity? What elements have no electronegativity?

Answer 23

Each element has an Electronegativity value regardless shows how strongly it attracts electrons in a covalent bond. Electronegativity is the ability to attract the bonding electron towards itself in a covalent bond. Noble gases have no electronegativity

Question 24

How does electronegativity differ across a period and down a group and why? What happens if an element A is slightly more electronegative than element B, or if A and B are both equal in electronegativity or if B is a lot more electronegative than A?

Answer 24

Across a period, electronegativity increases as protons increase and down a group electronegativity decreases as electron shielding increase.

If B is slightly more electronegative than a then B is partially negative and A is partially positive, if A and B have similar electronegativity there is no charge as they pull the electrons equally, and if B is a lot more electronegative than A then it forms ions and B is negatively charged and A is positively charged.

Question 25

How do you determine if a bond is nonpolar, polar or ionic using electronegativity of atoms?

Answer 25

Firstly, find the difference between the electronegativity of the atoms bonded. Then: - 0- below 0.5 is non polar (electrons equally shared between atoms) - 0.5 or 0.5-2.0 is polar (electrons are slightly attracted to one element more than another making it partially negative and partially positive) - 2.0 or above is ionic (one atom is completely more electronegative than another creating ions)

Question 26

If an atom has a larger electronegativity value, what partially charged value is it compared to a smaller electronegativity value?? What is a dipole and where is it found?

Answer 26

An atom with a large electronegativity value has the partially negative charge while the atom with the smaller electronegativity value has the partially positive charge. A dipole is an arrow with a line through it and it shows the direction of the electron pull, it only happens in a polar bond and it points towards the more partially negative atom as it shows how the electrons move towards the atom making it more partially negative.

Question 27

How does symmetrical and asymmetrical relate to nonpolar and polar bonds? How can a dipole cancel out and how does it relate to symmetrical and asymmetrical?

Answer 27

Nonpolar bonds share electrons equally, so are symmetrical and polar bonds share electrons unequally so are asymmetrical. However, when dipoles are arranged evenly around the central atom and the dipoles are the same length and cancels out when they pull in the opposite direction, it turns the molecule into a nonpolar molecule despite having polar bonds in the atoms itself.

Question 28

Definition for intermolecular forces? What are the three intermolecular forces?

Answer 28

Weak interactions between diples of different molecules which can be easily broken. The three intermolecular forces are London forces (AKA induced dipole-dipole interactions), permanent dipole-dipole interactions, hydrogen bonds.

Question 29

What are London forces?/ Induced dipole-dipole interactions? What does the size of London force depend on??

Answer 29

London forces occur in all molecules and atoms. London force occurs when electrons in an atom momentarily move to one side creating a partially negative and partially positive side which creates a instantaneous dipole which can easily change as electrons repel each other. This creates an induced dipole. The size of London force depends on number of electrons present.

Question 30

What are permanent dipole-dipole interactions? Where is it found and how is it different from London force? Why does a polar molecule not always have permanent dipole dipole interactions?

Answer 30

Permanent dipole-dipole interactions occur in any polar molecule and it is when an atom within a molecule is permanently partially positive or partially negative due to being electronegative and attracting the electrons more. This partially negative or partially positive force attracts other molecules that may also have this partially positive or negative force. This force of attraction is called permanent dipole-dipole interactions. Unlike London force, the dipole does not change. This is because dipoles may cancel out when molecule experiences as a symmetrical overall negative or positive charge creating no permanent dipole.

Question 31

What is a hydrogen bond and where does it occur? What is the difference between a hydrogen bond and a permanent dipole-dipole interaction?

Answer 31

A hydrogen bond is when a positive hydrogen ions is attracted to a partially negative ion with one or more lone pairs. This occurs between an H+ ion and a fluorine, oxygen or nitrogen atom. All H bonds are permanent dipole-dipole interactions but not all permanent dipole-dipole interactions are H bonds!

Question 32

What are properties of water that is caused by h-bonds? Three properties! Where are H bonds also found in our body?

Answer 32

- H bonds require lots of energy to break which gives water a high boiling or melting point. - ice is less dense on water because water molecules are arranged into an order structure. When the freezing point 0 C is reached. This ordered structure is stabilised by a network of hydrogen bonds that make the water molecules freeze further apart than in liquid water, allowing ice to float on water. - water has a high surface tension due to extra intermolecular bonding from hydrogen bonds. ---> each bonds are also found in our DNA structure. When nitrogen bases bond to each other, such as A and T having two hydrogen bonds and C and G having three hydrogen bonds.

Question 33

What must you always include when you draw the three intermolecular forces?

Answer 33

- London forces must include partially positive or partially negative sign. - permanent dipole-dipole interactions must include partially positive and partially negative sign and a dotted line if you want to include the permanent dipole dipole interaction - hydrogen bonds must include partially positive or partially negative sign, lone pairs and dotted lines to represent hydrogen bond

Question 34

Definition for periodicity?

Answer 34

When elements are arranged in order of atomic number, those having similar properties both chemical and physical recur periodically, such as at regular intervals

Question 35

What happens to ionization energy across a period and down a group and why, the three reasons?

Answer 35

Across a period: Shielding stays the same, nuclear charge increases, atomic radius decreases, ionization energy increases. Down a group: shielding increases, nuclear charge increases, atomic radius increases, ionization energy decreases.

Question 36

In a full isotopic symbol is the mass number on the top or bottom? And where is the atomic number?

Answer 36

Mass numbers on the top and atomic numbers on the bottom

Question 37

Electrons in an atom are arranged in orbitals, What is meant by the term orbital?

Answer 37

A region of an atom where there is high probability of finding an electron

Question 38

Define the term relative atomic mass?

Answer 38

The weighted average mass of the atoms of an element compared with 1/ 12 of the mass of a carbon-12 atom

Question 39

How will the chemical properties of two isotopes of one element differ?

Answer 39

There's no difference as chemical properties depend on electrical configuration!

Question 40

How many electrons does each subshell hold? How many electrons does each orbital hold?

Answer 40

S- 2 P-6 D-10 F-14 Each orbital only holds two electrons!!! ORBITAL== 2 ELECTRONS!!

Question 41

How do you find how many orbitals there are in different numbers of energy level (What is the equation)? (Such as the first energy level, the second energy level, the second energy level, the third energy level and the fourth energy level)

Answer 41

The equation is n squared - the first energy level is 1 squared which is 1 - the second energy level is 2 squared which is 4 - the third energy level is 3 squared which is 9 - the fourth energy level is 4 squared which is 16

Question 42

How do you find the number of electrons in each energy level? (Equation for it) For example, how many electrons is in the second energy level?

Answer 42

The equation is 2N squared as each orbital holds two electrons. In the second energy level it is 2* 2 squared which is eight electrons

Question 43

what is a standard solution

Answer 43

A standard solution is a chemical solution with an accurately known concentration.

Question 44

How are elements in a periodic table ordered by?

Answer 44

Elements are ordered by atomic number not atomic mass!

Question 45

How to tell if an element or molecule has a ionic covalent or metallic bond or if they're giant or simple?

Answer 45

All ionic compounds are giant. Ionic lattices, all metallic molecules are giant metallic lattices, giant covalent compounds often have carbon or silicon-based structures and have a high boiling/ melting point, simple covalent molecules have weak intermolecular forces and have a low boiling/ melting point

Question 46

Why is the electronic configuration an example of a periodic trend?

Answer 46

Across the period, the s subshells are filled first followed by P Subshells, the same pattern or trend of filling subshells repeats in other periods

Question 47

Difference between silica and silicon?

Answer 47

Silica- oxygen and silicon compound Silicon- natural element itself (si)

Question 48

What is a systematic name?

Answer 48

A standardised chemical name for a compound based on its molecular structure