Ch.13.2

Question 1

___________________________________ (________-__________) first developed the Periodic Table. He arranged the __________________ that were discovered back then in the ___th century into the Periodic Table.

Answer 1

Russian chemist Dmitri Mendeleev (1834-1907); 63 elements, 19

Question 2

How did Mendeleev arrange the elements in the Periodic Table?

Answer 2

He arranged them in a table according to the mass of atoms.

Question 3

Why did Mendeleev group eight elements together in a row in his Periodic Table?

Answer 3

This is because the columns of the table would contain elements with similar properties if he did so.

Question 4

In the modern Periodic Table, there are ___________________________________ elements. They are arranged in order of ___________________________________.

Answer 4

more than 110, increasing atomic number

Question 5

There are ________ main groups in the modern Periodic Table. Each group has a number (______________________________).

Answer 5

eight, I, II, III, IV, V, VI, VII, or 0

Question 6

The elements in the same group have similar ___________________________; or, they ___________________________________________.

Answer 6

chemical properties, react similarly to the same substances

Question 7

What is the use of carbon in the experiment in which we add group II elements to hydrochloric acid and observe their reactions?

Answer 7

It acts as a control set-up.

Question 8

What are the three dependent variables in the experiment in which we add group II elements to hydrochloric acid and observe their reactions? Describe the results of calcium and magnesium in this experiment.

Answer 8

Are gas bubbles given out, is heat released, and what gas is produced (if any). Gas bubbles are given out, heat is released, and hydrogen is produced.

Question 9

Name three safety precautions that we should follow while investigating the chemical properties and reactivities of elements in the same group.

Answer 9

Wear safety goggles and protective gloves
Wash your hands thoroughly after the experiment
Handle the acid with care

Question 10

Elements in the same group differ in _________________.

Answer 10

Reactivities

Question 11

Describe and explain the relationship between the reactivities of atoms and their position in a group of the Periodic Table.

Answer 11

Reactivity increases (atoms that form cations)/ decreases (atoms that form anions) down a group in the Periodic Table.
Cations are formed through the loss of electrons in an atom, while anions are formed through the gain of electrons in an atom.
As the number of shells in elements increases down a group in the Periodic Table, the distance between the outermost shell electrons and nucleus increases too, leading to a decrease in the attraction force between them;
Hence making it easier/ harder for atoms that form cations/ atoms that form anions to lose/ gain electrons.

Question 12

Name two experiments that we can carry out to compare the action of dilute hydrochloric acid on calcium and magnesium. Describe the result of setup 1. Why do both of these setups work?

Answer 12

Measuring the time taken for the metal to produce a specific amount of gas through the displacement of water.
Measuring the gas produced by the metal within a specific amount of time through the displacement of water.
It takes less time for the water level to reach the marking when calcium is added to hydrochloric acid, meaning that calcium is more reactive.
This is because they share the same dependent variable — the reactivity of elements.

Question 13

Describe the procedures in the displacement of water. (remember that this is not the complete procedure of the experiment in textbook)

Answer 13

Make a mark at about two thirds from the bottom of a test tube, then fill the test tube to the top with tap water.
Place it upside-down in a beaker half filled with water, and put the end of the delivery tube under the mouth of the test tube.
Fill a boiling tube with [liquid reactant]. Using a spatula, add [solid reactant] to the acid. Immediately fit the stopper with the delivery tube into the boiling tube.

Question 14

Can we still compare the reactivity of elements if the measurement of volume of gas produced and time of experiment are both different?

Answer 14

Yes. We can do this by comparing the ratio of volume of gas produced to the time taken in seconds in the reactions between hydrochloric acid and calcium/ magnesium respectively.

Question 15

Name the group, use and properties that makes it suitable for the purposes they are used for of helium.

Answer 15

Group 0; filling balloons; helium is extremely stable and less dense than air, allowing balloons to float in air.

Question 16

Name the group, use and properties that makes it suitable for the purposes they are used for of lithium.

Answer 16

Group I; making lithium ion batteries for mobile phones, computer etc; lithium is highly reactive, hence allowing a lot of energy to be stored in its atomic bonds.

Question 17

Name the group, use and properties that makes it suitable for the purposes they are used for of magnesium.

Answer 17

Group II; added to fireworks to produce brilliant white sparks; magnesium burns a brilliant white light.

Question 18

Name the group, use and properties that makes it suitable for the purposes they are used for of aluminium.

Answer 18

Group III; making soft drink cans; aluminium is very malleable and low in density.

Question 19

Name the group and use of silicon.

Answer 19

Group IV; making glass.

Question 20

Name the group, use and properties that makes it suitable for the purposes they are used for of red phosphorus.

Answer 20

Group V; making matches; red phosphorus is extremely flammable.

Question 21

Phosphorus exists in ____________________ with ________________________ and ________________________ being the most common ones.

Answer 21

different forms, red phosphorus, white phosphorus

Question 22

Name the group and use of oxygen.

Answer 22

Group VI; used to help patients with breathing difficulties.

Question 23

Name the group, use and properties that makes it suitable for the purposes they are used for of chlorine.

Answer 23

Group VII; killing germs in swimming pools and drinking water; chlorine reacts with water to form a solution that can be used as a disinfectant or bleach.

Question 24

Name the group and use of vanadium.

Answer 24

It is a transition element; it is used in the production of dyes.

Question 25

Name the group and use of neon.

Answer 25

Group 0, used in advertising signs.