ATOMIC STRUCTURE

Which one of the following electron configurations represents an element that forms a monoatomic ion with a charge of -2?
1. 1s²2s²
2. 1s²2s²2p²
3. 1s²2s²2p⁴
4. 1s²2s²2p⁶
In the graphite crystal lattice, what is the number of nearest covalently bonded neighbours for each carbon atom?
1. 3
2. 4
3. 5
4. 6
Which one of the following statements is true?
1. H₂O has a greater molecular polarity (dipole moment) than H₂S
2. H₂O is polar, but H₂S is non-polar
3. The molecules H₂S and H₂O are both linear
4. The molecules H₂S and H₂O both have zero molecular polarity (dipole moment).
The table below gives information about three pure solids designated X,Y and Z.

X Y Z
Approximate Melting Point ^oC 800 3500 1500
Electrical Conductivity in the solid state nil moderate High
Electrical conductivity in the liquid (molten) state high cannot be easily treated high

Which one of the following describes the bonding present in the three substances?
1. X is covalent molecular, Y is covalent network, Z is ionic
2. X is ionic, Y is covalent network, Z is metallic
3. X is ionic, Y is metallic, Z is metallic
4. X is covalent molecular, Y is metallic, Z is ionic
Which one of the following statements about graphite and diamond is true?
1. They have the same crystal lattice structure
2. They have the same degree of hardness
3. They have the same electrical conductivity
4. They can undergo the same chemical reactions
Species 'X' has the valence electron configuration of s², and 'Z' has the valence electron configuration of s²p⁵. Which of the following is the most likely formula of a compound formed between 'X' and 'Z' ?
1. XZ
2. XZ₂
3. X₂Z₅
4. X₂Z₇
An element has the first five successive ionisation energies as shown on the graph.

Which one of the following is it?
1. aluminium
2. calcium
3. carbon
4. neon
What is the maximum number of unpaired electrons possible in 3d orbitals?
1. 3
2. 5
3. 6
4. 10
In which one of the following is the solid state maintained only by covalent bonding?
1. CO₂(s)
2. H₂O(s)
3. NH₄Cl(s)
4. SiO₂(s)
In which one of the following substances is hydrogen bonding th main intermolecular force at room temperature?
1. ethanol
2. hydrogen bromide
3. hydrogen sulphide
4. methane
Which of the following elements has the lowest first ionisation energy?
1. B
2. Be
3. K
4. Mg
Which of the following is the electron configuration of N^3-?
1. 1s²2s²
2. 1s²2s²2p³
3. 1s²2s²2p⁶
4. 1s²2s²2p⁶3s²3p¹
Which one of the following ions does not have the electronic configuration 1s²2s²2p⁶3s²3p⁶ ?
1. Br^-
2. Ca²⁺
3. Cl^-
4. S^2-
Which one of the following is true of the atoms of a given element?
1. The number of neutrons must be greater than the number of electrons
2. The number of protons must be equal to the number of neutrons
3. The number of protons must be equal to the number of electrons
4. The number of protons must be greater than the number of neutrons
On which one of the following does the type of bond formed between two atoms depend?
1. Their atomic weights
2. Their electronegativities
3. The electrical conductivity of the compound
4. The melting and boiling point of the compound
Element A has the valence electron configuration of s² and element B has the valence electron configuration of s²p⁵. What will be the most likely formula of the compound formed between the two elements?
1. AB
2. AB₂
3. A₂B
4. AB₃
Which statement best describes a covalent bond?
1. The atoms have a noble gas electron configuration
2. The atoms have formed an infinite network
3. There is greater attraction of electrons to the more electronegative atom
4. There is simultaneous attraction of both nuclei to a shared electron pair
Which one of the following compounds contains only covalent bonds between its atoms?
1. CO₂
2. KNO₃
3. NaCl
4. NH₄Cl
How many orbitals can be found in the d subshell of the 3^rd principal energy level?
1. 3
2. 5
3. 8
4. 10
Which of the following substances contains dispersion forces?

I CO₂
II CH₃CH₂OH
III SiO₂
1. I only
2. I and II only
3. I, II and III
4. None of the given answers
Consider the following set of successive ionisation energies (MJ mol^-1).

0.74 ; 1.45 ; 7.73 ; 10.54 ; 13.63

Which of the following elements is most likely to have such a set of ionisation energies?
1. C
2. K
3. Mg
4. O
Which of the following has the highest first ionisation energy?
1. F
2. Mg
3. S
4. Si
Which one of the following determines which element an atom will be?
1. Its electric charge
2. Its electron configuration
3. Its number of neutrons
4. Its number of protons
An element 'X' forms a chloride XCl₃. Which can not be X?
1. Al
2. Fe
3. N
4. Sr
Which one of the following may have 17 protons, 19 neutrons and 18 electrons?
1. Cl
2. Cl^-
3. K
4. K⁺
For an element X, the first five successive ionisation energies can be represented on the following graph.

What would be the formula of the compound formed when X reacts with chlorine?
1. XCl
2. XCl₂
3. XCl₃
4. XCl₄
Which of the following arranges the substances in order of increasing ionisation energy?
1. F < Mg < Si < S
2. F < S < Si < Mg
3. Mg < S < Si < F
4. none of the given answers
Consider the following structures

Which of the following statements is true?
1. I and II are ions
2. I and III are ions
3. II and III are ions
4. None of I, II and III are ions
Which one of the following descriptions best applies to the term ' valence electrons'?
1. electrons in the s and p orbitals
2. electrons which are lost when bonds form
3. electrons in the outer energy level
4. electrons which make up a noble gas electron configuration
How many valence electrons are present in a nitrite ion NO₂^-?
1. 1
2. 17
3. 18
4. 24
Which of the following will have the highest melting point?
1. carbon dioxide
2. nitrogen dioxide
3. silicon dioxide
4. sulfur dioxide
Which one of the following lists the attractive forces in decreasing order (strongest to weakest)?
1. hydrogen bonding > ionic bonding > dispersion forces
2. covalent bonding > hydrogen bonding > dispersion forces
3. covalent network > dispersion forces > metallic bonding
4. hydrogen bonding > van der Waals forces > covalent bonding
Which one of the following statements about dispersion forces in a series of molecules is correct?
1. An increased molecular weight leads to a greater mass of the molecule and hence stronger dispersion forces
2. An increased number of protons and electrons leads to stronger dispersion forces
3. Larger electronegativity differences lead to stronger dispersion forces
4. The presence of an atom such as O or N bonded to H leads to stronger dispersion forces
An element Y has the electron configuration 1s²2s²2p⁵ and forms a compound XY² with element X. Which one of the following could be the electron configuration of X?
1. 1s²2s²
2. 1s²2s²2p¹
3. 1s²2s²2p²
4. 1s²2s²2p⁶3s¹
Which one of the following species has a different number of electrons from all the others?
1. Al³⁺
2. Ar
3. Ca²⁺
4. Cl^-
Which one of the following compounds contains only ionic bonds?
1. CH₃OH
2. HCl
3. NaH
4. NaNO₃
Which one of the properties of ammonia is not related to the hydrogen bonding between the molecules?
1. freezing point
2. molar mass
3. solubility in water
4. vapour pressure
Which of the following 1.00 mol L^-1 aqueous solutions will conduct electricity?

I hydrogen chloride
II ethanol
III ammonia
IV sodium nitrate
1. IV only
2. I and IV only
3. I, II and IV only
4. I, III and IV only
Which one of the following may have 19 protons, 21 neutrons and 19 electrons?
1. Ar
2. K
3. K⁺
4. Sc
Which best describes the bonding between Mg and Cl?
1. The atoms readily form ions which are attracted to each other
2. Polyatomic ions exhibit covalent bonding between the atoms within the ion
3. Mg and Cl form covalent bonds by sharing of electron pairs
4. There is a lattice of positive ions in a sea of delocalised electrons

	X	Y	Z
Approximate Melting Point ^oC	800	3500	1500
Electrical Conductivity in the solid state	nil	moderate	High
Electrical conductivity in the liquid (molten) state	high	cannot be easily treated	high

ATOMIC STRUCTURE

Multiple Choice Quiz on Atomic Structure