Electronic structure

Atoms of neon are made up of subatomic particles.

Figure 9 shows some information about the subatomic particles in neon atoms.

Complete Figure 9 with the missing information.

All atoms of neon have an atomic number of 10.

Describe what information about the number of subatomic particles can be obtained from the atomic number of neon.

Explain why atoms of neon are electrically neutral.

*(b) The structure of the periodic table and the position of the elements in the periodic table are linked to the electronic configuration of the elements.

Figure 10 shows the structure of the periodic table and the first 12 elements with their atomic numbers.

group

Use the first 12 elements shown in Figure 10 to explain

• how the structure of the periodic table is linked to the electronic configuration of the atoms of the elements

• how the arrangement of the elements is linked to their electronic configuration.

Nitrogen, N₂, oxygen, O₂and fluorine F₂ are all gases.

Nitrogen, oxygen and fluorine are in the same period of the periodic table.

Explain, in terms of electronic configuration, in which period of the periodic table nitrogen, oxygen and fluorine are located.

Fluorine has a boiling point of –188 °C.

Explain why fluorine has a low boiling point.

A mixture of nitrogen and oxygen becomes a liquid when cooled to –200 °C.

Which row shows the changes in energy and movement of the molecules as they are cooled from room temperature to –200 °C?

The mixture of liquid nitrogen and liquid oxygen can be separated.

Which process could be used to separate a mixture of liquid nitrogen and liquid oxygen?

At high temperatures, nitrogen, N₂, can react with oxygen, O₂, to form nitrogen dioxide only.

Write the balanced equation for this reaction.

Sodium carbonate has the formula Na₂CO₃.

Sodium carbonate contains Na⁺ ions and CO₃^2– ions.

The atomic number of sodium is 11.

What is the electronic configuration of the Na⁺ ion?

Explain why solid sodium carbonate cannot conduct electricity but a solution of sodium carbonate can conduct electricity.

Calculate the percentage by mass of sodium in sodium carbonate, Na₂CO₃.

(relative atomic masses: C = 12, O = 16, Na = 23)

percentage by mass of sodium =_........

*(c) A student has three solids, A, B and C.

The solids are sodium carbonate, powdered zinc and copper oxide, but the student does not know which solid is which.

The student reacted each solid with dilute sulfuric acid.

Figure 9 shows the student’s observations and the results of tests on any gases produced.

Use the observations and results in Figure 9 to identify which solid is which.

Your answer should include

• how each test result helps you to identify the solid

• word equations to support your answer.

Sodium carbonate has the formula Na₂CO₃.

Sodium carbonate contains Na⁺ ions and CO₃^2– ions.

The atomic number of sodium is 11.

What is the electronic configuration of the Na⁺ ion?

Explain why solid sodium carbonate cannot conduct electricity but a solution of sodium carbonate can conduct electricity.

Calculate the percentage by mass of sodium in sodium carbonate, Na₂CO₃.

(relative atomic masses: C = 12, O = 16, Na = 23)

percentage by mass of sodium =_........

Magnesium is a metal.

State one physical property of magnesium.

Which element is in the same group of the periodic table as magnesium? Use the periodic table to help you answer this question.

Magnesium atoms have 12 electrons.

Complete the electronic configuration of a magnesium atom.

The electronic configuration of a chlorine atom is 2.8.7

Explain how the electronic configuration of chlorine is linked to its period in the periodic table.

1.20 g of magnesium reacts completely with 3.55 g of chlorine to form magnesium chloride.

Calculate the empirical formula of the magnesium chloride.

(relative atomic masses: Mg = 24.0, C l = 35.5)

You must show your working.

empirical formula =_........

Sodium reacts with chlorine to form sodium chloride, which contains ionic bonds.

Hydrogen reacts with chlorine to form hydrogen chloride, which contains covalent bonds.

Figure 6 shows dot and cross diagrams of these compounds.

Describe the differences between an ionic bond and a covalent bond.

Figure 13 shows some information about some group 1 metals.

Explain, in terms of their electronic configurations, why these metals are placed in group 1 of the periodic table.

Which row shows two correct properties of group 1 metals?

The word equation for the reaction of potassium with bromine is

potassium + bromine potassium bromide

Add the missing state symbol and balance the equation for this reaction.

_........ K(_........ ) + Br₂(g) _........ KBr(s)

A sample of potassium contains three isotopes, potassium-39, potassium-40 and potassium-41.

Explain the meaning of the term isotopes.

*(e) The reactivity of the group 1 metals increases from lithium to caesium.

Often, teachers demonstrate the reactions of lithium, sodium and potassium with water.

These reactions can be used to predict the behaviour and reactions of rubidium and caesium with water.

Describe the reactions of each of the group 1 metals with water including the predicted behaviour and reactions of rubidium and caesium.

You may use word equations in your answer.

Magnesium carbonate has the formula MgCO₃.

Magnesium carbonate contains Mg²⁺ and CO₃²⁻ ions.

The atomic number of magnesium is 12.

What is the electronic configuration of the Mg²⁺ ion?

Explain why solid magnesium carbonate cannot conduct electricity but solid magnesium can.

Calculate the percentage by mass of magnesium in magnesium carbonate, MgCO₃.

(relative atomic masses: C = 12.0, O = 16.0, Mg = 24.0)

percentage by mass of magnesium =_........

Magnesium carbonate reacts with dilute hydrochloric acid. Water and carbon dioxide are two of the products of the reaction.

Complete the balanced equation for this reaction.

MgCO₃ + 2HCl _........ + H₂O + CO₂

This question is about potassium and zinc.

Which of the following temperatures is most likely to be the melting point of potassium?

Explain how the electronic configuration of an atom of potassium is related to its position in the periodic table.

Potassium reacts with oxygen to form potassium oxide.

Describe the test to show that a gas is oxygen.

Potassium oxide is ionic.

Write the electronic configurations for the ions in potassium oxide, K₂O.

potassium ion:_........

oxide ion:_........

Figure 4 shows two gas syringes connected by a glass tube.

Inside the glass tube there are some pieces of zinc. Zinc reacts with oxygen at a temperature of over 225 °C. Not all the oxygen reacts at once, the oxygen reacts only when in contact with the zinc.

Devise a plan to find the volume of oxygen contained in a known volume of air, using the apparatus shown in Figure 4.

Chlorine has an atomic number of 17.

Figure 3 shows the arrangement of electrons in an atom of chlorine.

What is the electronic configuration of this atom?

Explain, using Figure 3, why chlorine belongs to group 7 of the periodic table.

The nucleus of an atom is made up of protons and neutrons. Atoms of chlorine contain 17 protons.

Figure 4 shows some information about a proton, a neutron and an electron.

Explain, using the information in Figure 3 and Figure 4, why atoms of chlorine have no overall charge.

Atoms of chlorine-37 have a mass number of 37.

Calculate the number of neutrons in atoms of chlorine-37.

number of neutrons =_........

There are two isotopes of chlorine, chlorine-35 and chlorine-37.

Explain the meaning of the term isotopes.

Calcium has an atomic number of 20. A calcium atom has a mass number of 40.

Which row of the table shows the number of protons and number of neutrons in this atom of calcium?

Figure 6 shows the arrangement of electrons in an atom of calcium.

Explain, using the information in Figure 6, in which period of the periodic table calcium can be found.

Calcium and potassium react with water in similar ways.

One similarity in the reactions is that hydrogen gas is produced.

State one other similarity in the products of the reactions of calcium and potassium with water.

Potassium is higher in the reactivity series than calcium and reacts more vigorously with water than calcium reacts with water.

State why potassium is higher in the reactivity series and reacts more vigorously with water than calcium.

*(c) Calcium chloride can be prepared by the reaction of calcium with chlorine gas.

Figure 7 shows some properties of calcium, chlorine and calcium chloride.

Explain, in terms of bonding and structure, why the properties of the product, calcium chloride, are different from the properties of the reactants, calcium and chlorine.

An atom of potassium has atomic number 19 and mass number 39.

Give the electronic configuration of this potassium atom.

This potassium atom forms the ion K⁺.

Which row shows the number of protons and the number of neutrons in this potassium ion, K⁺?

Potassium and caesium are in the same group of the periodic table.

Explain, in terms of electrons, why potassium and caesium are in the same group.

Fluorine boils at –188C. There are forces between fluorine molecules.

Explain, in terms of these forces, why the boiling point of fluorine is low.

Potassium reacts with fluorine to form potassium fluoride. Potassium fluoride is a solid.

Complete the balanced equation for this reaction and add the state symbols.

_........ K (_........ ) + F₂(g) _........ KF (_........ )

What are the elements in group 1 of the periodic table called?

Figure 9 shows the melting points and boiling points of elements in group 7 of the periodic table.

Give, using Figure 9, the boiling point of bromine.

boiling point of bromine =_........ C

State which two elements from Figure 9 are solids at room temperature.

An atom of potassium has atomic number 19 and mass number 39.

Give the electronic configuration of this potassium atom.

This potassium atom forms the ion K⁺.

Which row shows the number of protons and the number of neutrons in this potassium ion, K⁺?

Potassium and caesium are in the same group of the periodic table.

Explain, in terms of electrons, why potassium and caesium are in the same group.

Fluorine boils at –188C. There are forces between fluorine molecules.

Explain, in terms of these forces, why the boiling point of fluorine is low.

Potassium reacts with fluorine to form potassium fluoride. Potassium fluoride is a solid.

Complete the balanced equation for this reaction and add the state symbols.

_........ K (_........ ) + F₂(g) _........ KF (_........ )

In Figure 5, the letters A, E, G, J, X and Z show the positions of six elements in the periodic table.

These letters are not the symbols of the atoms of these elements.

Using the letters A, E, G, J, X and Z

give the letters of the two elements that are non-metals

give the letters of two elements in period 2

give the letter of an element that normally forms an ion with a charge of +1.

Element E has an atomic number of 5. In a sample of E there are two isotopes. One isotope has a mass number of 10 and the other isotope has a mass number of 11.

Explain, in terms of subatomic particles, what is meant by the term isotopes.

All atoms of element E in this sample contain

Element X has an atomic number of 18.

State the electronic configuration of an atom of element X.

In an experiment, 3.5 g of element A reacted with 4.0 g of element G to form a compound.

Calculate the empirical formula of this compound. (relative atomic masses: A = 7, G = 16)

You must show your working.

empirical formula of this compound =_........

An oxygen atom has six electrons in its outer shell.

A hydrogen atom has one electron in its outer shell.

Complete the dot and cross diagram of a molecule of water, H₂O.

Show outer shell electrons only.

In Figure 1, the letters A, E, G, J, X and Z show the positions of six elements in the periodic table.

These letters are not the symbols of the atoms of these elements.

Using the letters A, E, G, J, X and Z

give the letters of the two elements that are non-metals

give the letters of two elements in period 2

give the letter of an element that normally forms an ion with a charge of +1.

Element E has an atomic number of 5. In a sample of E there are two isotopes. One isotope has a mass number of 10 and the other isotope has a mass number of 11.

Explain, in terms of subatomic particles, what is meant by the term isotopes.

All atoms of element E in this sample contain

Element X has an atomic number of 18.

State the electronic configuration of an atom of element X.

In an experiment, 3.5 g of element A reacted with 4.0 g of element G to form a compound.

Calculate the empirical formula of this compound. (relative atomic masses: A = 7, G = 16)

You must show your working.

empirical formula of this compound =_........

Some of the elements in the periodic table are metals.

The electronic configuration of a metal is 2.8.3

Which row shows the group and period of the periodic table where this metal is found?

Lithium, potassium and rubidium are alkali metals.

Describe what you would see when a small piece of rubidium is dropped on to water.

The electronic configuration of lithium is 2.1 The electronic configuration of potassium is 2.8.8.1 Lithium is less reactive than potassium.

Explain, in terms of their electronic configurations, why lithium is less reactive than potassium.

Lithium has two naturally occurring isotopes, lithium‑6 and lithium‑7.

A sample of lithium contains 7.59 % of lithium‑6 92.41% of lithium‑7.

Calculate the relative atomic mass of lithium in this sample.

Give your answer to two decimal places. You must show your working.

relative atomic mass of lithium =_........

(a) A chlorine atom contains 17 electrons, 18 neutrons and 17 protons.

State the mass number of this chlorine atom.

Give the electronic configuration of this chlorine atom.

Describe what you would see if damp, blue litmus paper is placed into chlorine gas.

Chlorine exists as diatomic molecules.

In a molecule, two chlorine atoms are joined by a covalent bond.

Describe what is meant by a covalent bond.

Explain why chlorine is a gas, rather than a liquid, at room temperature.

When the gas hydrogen chloride, HC l, is dissolved in water, a solution forms. Blue litmus paper dipped in this solution turns red.

State why the litmus paper turns red.

Figure 7 lists the halogens in the order in which they appear in group 7 of the periodic table.

The melting points of four of the halogens are given.

Estimate the melting point of iodine.

_........ °C

Bromine reacts with heated iron.

Give the name of one halogen that would react with iron more vigorously than bromine.

(a) A chlorine atom contains 17 electrons, 18 neutrons and 17 protons.

State the mass number of this chlorine atom.

Give the electronic configuration of this chlorine atom.

Describe what you would see if damp, blue litmus paper is placed into chlorine gas.

Chlorine exists as diatomic molecules.

In a molecule, two chlorine atoms are joined by a covalent bond.

Describe what is meant by a covalent bond.

Explain why chlorine is a gas, rather than a liquid, at room temperature.

When the gas hydrogen chloride, HC l, is dissolved in water, a solution forms. Blue litmus paper dipped in this solution turns red.

State why the litmus paper turns red.