Topic 2 Part 3: More Periodicity

​Answers to Starter

Multiple Choice

What property is being measured in this diagram?

• Density

• Ionization Energy

• Atomic Radius

• Atomic Mass

Multiple Choice

Which element's atom is larger? Nitrogen or Phosphorus?

• Nitrogen

• Phosphorus

Multiple Select

As you go across a period in the periodic table, which of the following statements are correct?

• Electrons are in the same energy level and have the same shielding.

• Nuclear charge increases.

• Valence electrons are pulled closer to the nucleus.

• Atomic radii increase.

Multiple Choice

Which of these best explains the reasoning behind the trend that as you go across a period, size decreases?

• As you go across a period, more energy levels are added, which shrinks the atom.

• The added electrons in the nucleus give the atom a negative charge, which shrinks the atom.

• The added protons in the nucleus pull the electrons closer to them, which shrinks the atom.

• All of the above

Multiple Choice

As you move across the periodic table from left to right, the atomic radius decreases.  This is because - 

• the number of protons increases, so attraction to electrons increases
• the number of energy levels increases
• the number of electrons increases
• the atomic mass increases

Multiple Choice

As you move ______ a group, more energy levels are added, which increases the size of the atom

• down

• up

• diagonal

• away

Fill in the Blank

As you go down a group, the atomic radius ___ .

Multiple Choice

Which periodic group has the smallest atomic radius?

• Alkali metals
• Halogens
• Noble Gases
• Transition metals

Multiple Choice

Of the elements Ca, Be, Ba, and Sr, which has the largest atomic radius?

• Be
• Ba
• Ca
• Sr

Multiple Choice

Which of the following will have a larger radius than Zinc (Zn)?

• Gallium
• Aluminum
• Magnesium
• Strontium

Multiple Choice

Which statement correctly and completely identifies a trend?

• Atomic radius decreases across a period and increases down a group.
• Electronegativity decreases across a period and decreases down a group.
• Ionization energy increases across a period and increases down a group.
• Ionic radius increases across a period and increases down a group.

Multiple Choice

What is a cation?

• A negative ion formed from the gaining of electrons.

• A positive ion formed from the gaining of electrons.

• A negative ion formed from the loss of electrons.

• A positive ion formed from the loss of electrons.

Fill in the Blank

Cations are ___ than the atoms they come from.

Multiple Choice

Which is the smaller atom: Mg or Mg⁺²?

• Mg because it gains an energy level since it gains 2 electrons.

• Mg due to extra electron repulsion created by gaining 2 electrons.

• Mg⁺² because of extra electron repulsion created by gaining 2 electrons.

• Mg⁺² because it loses an energy level since it loses 2 electrons.

Multiple Choice

What is an anion?

• A negative ion formed from the gaining of electrons.

• A positive ion formed from the gaining of electrons.

• A negative ion formed from the loss of electrons.

• A positive ion formed from the loss of electrons.

Multiple Choice

What is the trend for ionic radius across a period for anions?

• increase

• decrease

• remain constant since they are all the same type of ion

Multiple Choice

What is the trend for ionic radius down a group?

• increase

• decrease

• remain constant

Multiple Choice

Which ion has the smaller radius?

• P^-3

• Cl^-1

• S^-2

• all are anions in the same period so they are the same size

Multiple Choice

Which is larger:

P or P^-3 ?

• P because it is the neutral atom.

• P^-3 because it lost 3 electrons.

• P^-3 because it gained 3 electrons.

• They are the same size since they are both P.

Multiple Choice

Arrange the following by decreasing ionic radius: Ag⁺¹, In⁺³, Cd⁺², Sn⁺⁴?

• Ag⁺¹, In⁺³, Cd⁺², Sn⁺⁴

• Ag⁺¹, Cd⁺², In⁺³, Sn⁺⁴

• Sn⁺⁴, In⁺³, Cd⁺², Ag⁺¹

• Sn⁺⁴, Cd⁺², In⁺³, Ag⁺¹

Multiple Choice

Which is the larger atom? Ca⁺², K⁺¹, Ga⁺³?

• Ca⁺²

• K⁺¹

• Ga⁺³

• they are all the same size since they are all cations

Multiple Choice

Isoelectronic species refer to...

• Groups of atoms and ions which have the same valence electrons.

• Groups of atoms and ions which have the same electronic configuration.

• Groups of atoms and ions which have the same n.

Multiple Choice

Na⁺ and Al³⁺ are isoelectronic species (1s² 2s² 2p⁶). Which of these ion is smaller?

• Na⁺

• Al³⁺

• I'm not sure

• They have the same size

Multiple Choice

What is the example of species that are isolectronic?

• Na⁺ and Si⁴⁺

• Na⁺ and Cl^-

• Mg²⁺ and Al ⁺

• S^2- and O^2-

Multiple Choice

What causes the largest changes in melting point across period 2 elements?

• change in bonding structure

• greater electronegativity

• greater number of electrons

• increase in nuclear charge

Multiple Choice

Which of the following best explains why metallic elements in Period 3 have high melting points?

• Because metallic elements have a sea of delocalised electrons and strong electrostatic attractions between positive ions and electrons.

• Because metallic elements have weak forces between their atoms.

• Because metallic elements have covalent bonds similar to diamond.

• Because metallic elements are monoatomic.

Multiple Select

Which factors contribute to the increase in melting point as you go across Period 3 from sodium to aluminium?

• Increase in the charge of the metal ion

• Increase in the number of delocalised electrons

• Decrease in atomic size

• Stronger metallic bonds

Multiple Select

TICK ALL THAT APPLY: Which of the following describe the properties of a giant covalent lattice?

• High melting point

• Conducts electricity as a solid

• Does not dissolve in any solvent

• Low melting point

Fill in the Blank

The molecules of phosphorus, sulfur, and chlorine are held together by weak ___ forces.

Multiple Choice

Which Period 3 element has the lowest melting point and why?

• Argon, because it is monoatomic and has very weak dispersion forces.

• Chlorine, because it forms simple molecules.

• Sodium, because it has a metallic structure.

• Silicon, because it has a giant covalent structure.

Multiple Choice

A substance has a high melting point, and conducts electricity in both solid and molten states. Which of the below describes the structure and bonding of the substance?

• Giant ionic lattice

• Giant covalent lattice

• Simple molecular

• Giant metallic

Multiple Choice

Which of these Period 3 elements has the highest melting point?

• Aluminium

• Phosphorus

• Sodium

• Sulfur

Multiple Choice

Which element in Period 3 has the highest melting point?

• Aluminium

• Silicon

• Sodium

• Sulfur

Multiple Choice

Which elements are shown in increasing order of the stated property?

• Atomic radius: phosphorus, sulfur, chlorine.

• First ionisation energy: sodium, magnesium, aluminium.

• Electronegativity: sulfur, phosphorus, silicon.

• Melting point: argon, chlorine, sulfur.

Multiple Choice

Which is the correct order of melting points of these Period 3 elements?

• phosphorus > sulfur > chlorine > argon

• argon > chlorine > phosphorus > sulfur

• sulfur > phosphorus > chlorine > argon

• chlorine > phosphorus > sulfur > argon

Multiple Choice

Which properties are typical of most non-metals in period 3?

I. They form ions by gaining one or more electrons.

II. They are poor conductors of heat and electricity.

III. They have high melting points.

• I and II only

• I and III only

• II and III only

• I, II and III

Multiple Choice

Which of the following is a correct statement about the trend in atomic radius across Period 3 of the Periodic Table?

• radius increases because the atoms have more electrons

• radius decreases because nuclear charge increases

• radius increases because shielding (screening) increases

• radius decreases because shielding (screening) decreases

Multiple Choice

Which set of elements in the solid state contain a simple molecular lattice, a giant covalent lattice and a giant metallic lattice?

• S, Si, Al

• P, Si, C

• S, P, Si

• Mg, P, S

Multiple Select

What is periodicity?

• A description of the periodic table

• The organization of elements into the periods

• The repeating pattern of physical and chemical properties of elements