Unit B Lesson 6: The Parts of the Periodic Table
Completion requirements
Unit B Lesson 6: The Parts of the Periodic Table
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Learning Targets |
Big Question: What can I learn from the periodic table?
The periodic table not only organizes the building blocks of matter, but it also holds large amounts of information about each element.
The periodic table not only organizes the building blocks of matter, but it also holds large amounts of information about each element.
At the end of this inquiry, you should be able to answer the following questions:
- What do the symbols on the periodic table represent?
- What are atomic number, atomic mass and mass number?
- What unit of measurement is used for atomic mass?
- How is the number of neutrons calculated?
- How are metals different from non-metals?
- On the periodic table, what separates metals from non-metals?
- How are metalloids different from metals and non-metals?
- How are families (groups) different from each other?
Pages 126 to 129, and 132 to 133 in your text will help you answer these questions about the parts of the periodic table.
Introduction
When you study Chemistry, you will find the periodic table organizes much information about all the known elements. Elements from the periodic table are used in our lives, such as
- aluminium in soft-drink cans
- lithium in watch batteries
- oxygen in air
- neon in signs
- uranium in nuclear power production
- phosphorus in matches
- When looking at a periodic table, you will see rows called periods.
- The columns are called groups or families.
- Elements in the same group have similar chemical and physical properties.
Watch
Periodic Table Patterns
Watch the following two videos to learn more about how the periodic table is organized.
Watch the following two videos to learn more about how the periodic table is organized.
Now that you know more about periodic table organization, try answering these two questions.
1. How many periods are in the periodic table?
2. How many groups are in the periodic table?
There are 7 periods
There are 18 groups.
Watch
All About Elements
Watch the following video to learn more about the elements of the periodic table.
Watch the following video to learn more about the elements of the periodic table.
Symbols of Elements
The first letter in an element symbol is always a capital letter. If there is a second letter, it is always lowercase. You do not need to memorize the element symbols. They can always be found on the periodic table. However, familiarity with the element symbols makes finding information on the periodic table easier.
Many of the element symbols are recognized and remembered quickly. Some element symbols contain one letter and reflect the English name of the element, such as O for oxygen, H for hydrogen, C for carbon, N for nitrogen, and P for phosphorus. Some symbols contain a capital and a lowercase letter. For example, the chemical symbol for argon is Ar and the symbol for neon is Ne, which are easy to remember.
Some symbols are trickier to remember because they were named using Latin or Greek words. In English, both phosphorus and potassium start with P. However, the symbol for potassium is K.
The first letter in an element symbol is always a capital letter. If there is a second letter, it is always lowercase. You do not need to memorize the element symbols. They can always be found on the periodic table. However, familiarity with the element symbols makes finding information on the periodic table easier.
Many of the element symbols are recognized and remembered quickly. Some element symbols contain one letter and reflect the English name of the element, such as O for oxygen, H for hydrogen, C for carbon, N for nitrogen, and P for phosphorus. Some symbols contain a capital and a lowercase letter. For example, the chemical symbol for argon is Ar and the symbol for neon is Ne, which are easy to remember.
Some symbols are trickier to remember because they were named using Latin or Greek words. In English, both phosphorus and potassium start with P. However, the symbol for potassium is K.
Phosphorus, P
From a Greek phrase that means 'morning light'.
Phosphorous glows faintly in oxygen.
From a Greek phrase that means 'morning light'.
Phosphorous glows faintly in oxygen.
Potassium, K
From the Medieval word 'kalium'.
In Latin, kalium means potash (pot ashes).
From the Medieval word 'kalium'.
In Latin, kalium means potash (pot ashes).
Is it important to use capital and lowercase letters correctly? Is there a difference between CO and Co?
CO is a compound called carbon monoxide.
It has one carbon atom and one oxygen atom.
It has one carbon atom and one oxygen atom.
Co is an element called cobalt.
Watch this video to see the interesting origin of some element names.
Watch
All About Atoms, Atomic Number, and Atomic Mass
Watch the following video to learn more about atoms, atomic number, and atomic mass.
Watch the following video to learn more about atoms, atomic number, and atomic mass.
Atomic Numbers
The atomic number is the number of protons in an atom.
- In a neutral atom, the atomic number is also the number of electrons in an atom because the number of positive charges must equal the number of negative charges.
- The number of protons determines the type of atom it is.
The top left corner indicates the number of protons in sulfur. Every sulfur atom has 16 protons in its nucleus and 16 electrons in a cloud around the nucleus.
Every nitrogen atom has 7 protons in its nucleus and 7 electrons in a cloud surrounding the nucleus.
How many electrons are in a silicon atom?
How many protons are in a boron atom?
Because its atomic number is 14,
a silicon atom has 14 electrons.
a silicon atom has 14 electrons.
Because the atomic number of boron is 5,
a boron atom has 5 protons.
a boron atom has 5 protons.
Atomic Mass
The atomic mass is the total mass of the atom. The atomic mass unit (amu) is used to measure the mass of an atom. One amu is equal to the mass of approximately 1 proton or 1 neutron. 1836 electrons have the same mass as one proton; therefore,
the mass of an electron is much smaller than that of a proton or neutron.
The bottom number indicates the mass of the average sulfur atom; 32.066 atomic mass units (amu).
The bottom number indicates the mass of the average nitrogen atom; 14.00674 amu.
Mass Number
The mass number of an element is always larger than the atomic number is.
To calculate the mass number, this equation is used:
- The mass number is equal to the sum of the number of protons and neutrons in the atom.
- Because the mass of electrons is so small, they are not calculated into the mass number of an element.
To calculate the mass number, this equation is used:
mass number = the number of neutrons + the number of protons (the atomic number)
A visual representation of the mass number of oxygen. Oxygen's atomic number is 8. Its mass number is 16. The number of neutrons in an oxygen atom is therefore 16 β 8 = 8.
A visual representation of the mass number of fluorine shows an atomic number of 9, and a mass number of 19. The number of neutrons in a fluorine atom is therefore 19 β 9 = 10.
SINCE
the number of neutrons + number of protons = mass number
THEN
the mass number β number of protons = number of neutrons
the number of neutrons + number of protons = mass number
THEN
the mass number β number of protons = number of neutrons
How many neutrons are in carbon?
How many neutrons are in cobalt?
mass number β # of protons = # of neutrons
Carbon has an atomic number of 6, so it has 6 protons.
The mass number of 12.011 is rounded to 12.
mass number β # of protons = # of neutrons
12 β 6 = # of neutrons
12 β 6 = 6 neutrons
Carbon has an atomic number of 6, so it has 6 protons.
The mass number of 12.011 is rounded to 12.
mass number β # of protons = # of neutrons
12 β 6 = # of neutrons
12 β 6 = 6 neutrons
mass number β # of protons = # of neutrons
Cobalt has an atomic number of 27 so it has 27 protons.
The mass number of 58.9332 is rounded to 59.
mass number β # of protons = # of neutrons
59 β 27 = # of neutrons
59 β 27 = 32 neutrons
Cobalt has an atomic number of 27 so it has 27 protons.
The mass number of 58.9332 is rounded to 59.
mass number β # of protons = # of neutrons
59 β 27 = # of neutrons
59 β 27 = 32 neutrons
Watch
To solidify your knowledge of atomic structure watch "Atomic Number and Mass Number".
Check Your Understanding
Atomic Mass and Atomic Number
1. What is the atomic number of lithium?
The atomic number is the number found at the top of every element.
Lithium's atomic number is 3.
Lithium's atomic number is 3.
3. What is the mass number of lithium?
The mass number is the larger number found with each element.
Lithium's mass number is 7 (rounded up from 6.941).
Lithium's mass number is 7 (rounded up from 6.941).
2. How many protons does lithium have?
Atomic number = number of protons.
Lithium has 3 protons.
Lithium has 3 protons.
4. How many neutrons does lithium have?
The number of neutrons in an atom is the mass number β the atomic number.
Lithium has a mass number of 7.
Lithium has an atomic number of 3.
7 β 3 = 4
Lithium has 4 neutrons.
Lithium has a mass number of 7.
Lithium has an atomic number of 3.
7 β 3 = 4
Lithium has 4 neutrons.
Try It!
Practice Worksheet: Using the Periodic Table
- If you do not have a copy ready, click on the image to the right to open a periodic table in a new window.
- DOWNLOAD this practice worksheet (S9_UB_S2_L6a_using_periodic_table). If you prefer to use a Google Drive or PDF version of the worksheet, click here.
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Complete the Skill Practice on page 129 of Science in Action 9 and then complete the worksheet.
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When you are satisfied with your responses you can check your work by clicking on the "SUGGESTED ANSWERS" button below.
Wait! Don't view the suggested answers first. This practice work is not for marks, it is meant to help you check your understanding. Check the answers AFTER doing the questions! Keep the practice worksheet for study purposes. If you don't understand something, contact your teacher!
Watch
Before we continue, let's watch a fabulous review of the nucleus in "The Nucleus: Crash Course Chemistry #1".
Classification of Metals, Non-Metals, and Metalloids
On the periodic table, a bold zigzag line runs from just left of boron (#5) to the lower right-hand corner of the table where it stops at iodine (#53). This staircase line separates elements that are metals from those that are non-metals.
Often, elements touching the staircase have some properties of both metals and non-metals, so they are called metalloids. The metalloids (B, Si, Ge, As, Sb, Te, and At) are green on the periodic table in Figure 1.
On the periodic table, a bold zigzag line runs from just left of boron (#5) to the lower right-hand corner of the table where it stops at iodine (#53). This staircase line separates elements that are metals from those that are non-metals.
Often, elements touching the staircase have some properties of both metals and non-metals, so they are called metalloids. The metalloids (B, Si, Ge, As, Sb, Te, and At) are green on the periodic table in Figure 1.
Figure 1 β The "staircase" line on the periodic table separates elements as metals, non-metals, and metaloids.
Look at the various metals in Figure 2. Can you find any of the metals from the image on the periodic table? Do you see any metals that are pure substances? Copper (Cu) and Aluminium (Al) are pure metals. All pure metals are silver
in colour except for copper and gold.
Often in our world, we combine pure metals to produce new substances that are called alloys. Alloys contain more than one type of element.
Often in our world, we combine pure metals to produce new substances that are called alloys. Alloys contain more than one type of element.
- Brass contains copper and tin.
- Bronze contains zinc and copper.
- Cast iron contains iron, silicon (a metalloid), and carbon (a non-metal).
- Steel contains iron and carbon.
Figure 2 β Various metals
Try It!
Practice Worksheet: Introduction to the Periodic Table
- DOWNLOAD this practice worksheet (S9_UB_S2_L6b_metals_nonmetals). If you prefer to use a Google Drive or PDF version of the worksheet, click here.
-
Answer the questions on the worksheet as you watch the video below "Introduction to the Periodic Table".
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When you are satisfied with your responses you can check your work by clicking on the "SUGGESTED ANSWERS" button below.
Wait! Don't view the suggested answers first. This practice work is not for marks, it is meant to help you check your understanding. Check the answers AFTER doing the questions! Keep the practice worksheet for study purposes. If you don't understand something, contact your teacher!
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The metals are located to the left of the staircase line.
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The non-metals are located to the right of the staircase line.
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- solid (exception is Hg which is a liquid)
- malleable
- lustre (shiny)
- good conductors
- opaque (do not allow light through)
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- can be solids, liquids or gases
- brittle
- dull (non-shiny)
- non-conductors
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greater variety in appearance
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Metalloids are located on the staircase line.
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The metalloids are boron, silicon, germanium, arsenic, antimony, tellurium, and astatine.
Can we determine if an element is a metal or non-metal by its properties? We can ask ourselves the following five questions to determine if the substance is a metal or non-metal. If the answers are βyesβ, it is a metal. If the answers are
βnoβ, the element is a non-metal.
Our first sample element is tin.
Our next sample element is gold.
Our third element is oxygen.
Did you answer "yes" or "no" to the questions?
Did you answer "yes" or "no" to the questions?
Did you answer "yes" or "no" to the questions?
Tin is definitely a metal.
The answers to all the questions are "yes", so gold is a metal.
The answer to all these questions is "no". Therefore, oxygen is a non-metal.
Important Groups/Families
Group 1 Alkali Metals
The alkali metals, located in group 1 of the periodic table, are very reactive metals that do not occur freely in nature. As with all metals, the alkali metals
- are usually shiny
- are dense
- conduct electricity and heat
- are malleable
- are solid
The alkali metals are softer than most other metals. Cesium and francium are the most reactive elements in this group. Alkali metals can explode if they are exposed to water.
They are called alkali metals because, when they react with water, they form alkaline (basic) solutions. You will learn more about basic solutions in the next unit.
Hydrogen is above the alkali metals in the periodic table; however, it is not part of group.
Figure 3 β Alkali metals, like this sample of lithium, are often stored with wax or oil inside glass containers.
Check Your Understanding
Watch the video "Alkali Metals" (below), which demonstrate the violent reactions of group 1 metals. As you watch, answer the following questions.
1. Which alkali metal (group 1 metal) is the most reactive?
2. Which alkali metal (group 1 metal) is the least reactive?
3. Why do you think that francium was not tested?
1. Which alkali metal (group 1 metal) is the most reactive?
cesium
lithium
too dangerous
Group 2: Alkaline-Earth Metals
The alkaline-earth metals are beside the alkali metals (group 1). This is the second most reactive family of elements in the periodic table. As with all metals, the alkaline-earth metals:
The alkaline-earth metals are beside the alkali metals (group 1). This is the second most reactive family of elements in the periodic table. As with all metals, the alkaline-earth metals:
Alkaline-earth metals are harder and denser than alkali metals. They are called alkaline because, when these compounds are mixed in water, they are likely to form solutions with a pH greater than 7. The higher pH levels mean that they are basic or alkaline solutions.
- are shiny
- are dense
- conduct electricity and heat
- are malleable
- are solid
Figure 4 β Calcium is an alkaline-earth metal.
Check Your Understanding
As you watch "Chemistry of the Group 2 Elements (Reactivity with Water)", which demonstrate the violent reactions of group 2 metals, answer questions 1-2:
1. Which alkaline-earth metal (group 2 metal) is the most reactive?
barium
berylium
Group 17: Halogens
The halogens are five non-metallic elements found in group 17 of the periodic table. As with all non-metals, the halogens...
are dull
are brittle
are non-conductors
are insulators
can be a gas, a liquid or a solid
They are all toxic and are the most reactive non-metals. Often, halogens react with the alkali metals (group 1) and the alkaline-earth metals (group 2).
The term "halogen" means "salt-former", and compounds containing halogens are called "salts". At room temperature, the halogens exist in all three states of matter.
The halogens are five non-metallic elements found in group 17 of the periodic table. As with all non-metals, the halogens...
They are all toxic and are the most reactive non-metals. Often, halogens react with the alkali metals (group 1) and the alkaline-earth metals (group 2).
The term "halogen" means "salt-former", and compounds containing halogens are called "salts". At room temperature, the halogens exist in all three states of matter.
- fluorine: light-coloured gas
- chlorine: greenish-yellow gas
- bromine: orange-brownish liquid that evaporates
- iodine: solid that sublimes into purple gas
- astatine: a radioactive, black solid
Figure 5 β Halogens are all different states at room temperature. For example, iodine (shown here) is a solid.
Watch
Watch the video "Comparing the four Halogens" to see the variety of elements in this group.
Although halogens are toxic (inhaling them can kill you!), many halogen compounds are useful in everyday life. To learn more, watch "Halogens
and their Compounds".
Group 18: Noble Gases
The noble gases are located on the far right side of the periodic table (beside the halogens). All the noble gases are very stable, colourless, and odourless. Noble gases react very rarely with other substances.
The noble gases are located on the far right side of the periodic table (beside the halogens). All the noble gases are very stable, colourless, and odourless. Noble gases react very rarely with other substances.
- Used in balloons and airships, helium is much less dense than air is. Balloons filled with helium float upwards.
- Used in advertising signs, neon glows when electricity is passed through it. Various coloured neon lights can be made by coating the inside of the glass tubing of the lights with other chemicals.
- Used in light bulbs, argon prevents the filament from reacting with the oxygen and water in the air because argon is unreactive.
- Used in lasers, krypton lasers are used by surgeons performing laser eye surgery.
- Xenon is used in medicine as a general anesthetic and in medical imaging. In addition, it is used in photographic flashes.
Try It!
Practice Worksheet: Important Groups and Families
- DOWNLOAD the practice worksheet (S9_UB_S2_L6c_A3_groups_families). If you prefer to use a Google Drive or PDF version of the worksheet, click here.
- Complete the worksheet.
-
When you are satisfied with your responses you can check your work by clicking on the "SUGGESTED ANSWERS" button below.
Wait! Don't view the suggested answers first. This practice work is not for marks, it is meant to help you check your understanding. Check the answers AFTER doing the questions! Keep the practice worksheet for study purposes. If you don't understand something, contact your teacher!
- Eleven are gases; H, hydrogen; He, helium; N, nitrogen; O, oxygen; F, fluorine; Ne, neon; Cl, chlorine; Ar, argon; Kr, krypton; Xe, xenon; Rn, radon
- Bromine, Br; Mercury, Hg
- Magnesium, Mg
- Lead, Pb
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Question 6: Matching
