Unit A Energy and Matter in Chemical Change : Section 2.0 Flashcards
What is the foundation for everything?
The elements
How many elements are in the periodic table?
118
What are elements?
Substances that cannot be broken down
How many naturally occurring elements are there?
90
How many synthetic elements are there?
25
What are the three sections that all elements can be classified into?
Metals
Non-metals
Metalloids
What section do most elements fall into?
Metals
Which section has the least elements?
Metalloids
What are the six common characteristics of metalloids?
- Silver or gray
- Shiny
- Good conductors
- Malleable
- Ductile
- Solid at room temperature
How does mercury differ from other metals?
It is a liquid at room temperature
What is room temperature?
25°
What is an example of a variable characteristic of a metal?
-How strongly metals react with other substances.
Which metal is highly reactive with air and water?
Sodium
What are some examples of inert metals?
Gold and platinum
What does inert mean?
Unreactive
How many elements are non-metals?
17
Why are non-metals in a section together?
Because of their lack of resemblance to metal instead of their similarities
What type of bond are about half of the non-metals usually in? What name can we give these compounds?
molecular bond / covalent bond;
molecules
What type of variation is there in non-metals?
There is a lot of variation among non metals, particularly in colour and state. For example many are colorless gases but as liquids can be slightly colored like light blue liquid oxygen. Carbon is black when graphite and clear when diamond. Hydrogen, helium, and nitrogen are clear and colorless when gas or liquid. Sulphur is bright yellow and forms large crystals. Boron is black brown. Phosphorus has many different colours including colorless, waxy white, scarlet, red, violet, yellow, or black. P4 is white. Fluorine is pale yellow as a gas. Iodine appears violet as a gas but is nearly black as a solid (shiny and a hint of purple). Astatine is a black solid.
In contrast, metals are solid and usually silver except for copper, gold, and osmium. Copper is shiny and close in colour to a mix of red, orange and brown, gold is golden, and osmium is silvery blue.
What non-metal can etch glass?
Flourine
Hydrofluoric acid HFl and potassium fluoride KFl are used commonly
Which group on the periodic table is unreactive?
Noble gases
What are metalloids?
Elements that have properties that are intermediate between metals and non-metals
What properties does the periodic table organize elements by?
Chemical properties
Which side of the periodic table are the metals located on?
The left
Which side of the periodic table are the non-metals located?
The right
Where are the metalloids on the periodic table located?
In between the metals and non-metals
Above and below the staircase, not including aluminum, and not including the halogens. Start the staircase to the left and below Boron and go down to the right.
Why is hydrogen an exception? (context = metal vs. non-metal)
It is a non-metal but behaves like metal in chemical reactions
How does an element get its symbol?
Its often an abbreviation derived from the element’s name. Will have at least one uppercase letter. May also have a lower case letter as a second letter.
What is a Period?
Each horizontal row, where period 1 is the first row and period 2 is the second row in the periodic table etc.
What is a group?
Each vertical coulumn is considered a group; several of the groups have names such as the alkali metals are the left-most column.
alkali metals = 1st group
alkaline Earth metals = 2nd group
chalcogens = 16th group
halogens = 17th group
noble gases = 18th group
Families tend to be vertical groups but also consider other similarities and thus are not the same as groups. Think of the lanthanide and actinide series etc.
What are Chemical families?
Elements that have similar chemical and physical properties, not necessarily part of the same group, but can be.
Alkali metals
Alkaline earth metals
Transition metals
Halogens
Noble gases
For more in depth knowledge:
Science, Tech, Math›Science
Element Families of the Periodic Table

Elements are grouped into families in the periodic table.Digital Art / Getty Images
By
Anne Marie Helmenstine, Ph.D.
Updated on October 27, 2019
Elements may be categorized according to element families. Knowing how to identify families, which elements are included, and their properties helps predict behavior of unknown elements and their chemical reactions.
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Element Families

Element families are indicated by numbers located at the top of the periodic table.
Todd Helmenstine
An element family is a set of elements sharing common properties. Elements are classified into families because the three main categories of elements (metals,nonmetals, and semimetals) are very broad. The characteristics of the elements in these families are determined primarily by the number of electrons in the outer energy shell.Element groups, on the other hand, are collections of elements categorized according to similar properties. Because element properties are largely determined by the behavior of valence electrons, families and groups may be the same. However, there are different ways of categorizing elements into families. Many chemists and chemistry textbooks recognize five main families:
5 Element Families
Alkali metals
Alkaline earth metals
Transition metals
Halogens
Noble gases
9 Element Families
Another common method of categorization recognizes nine element families:
Alkali Metals: Group 1 (IA) - 1 valence electron
Alkaline Earth Metals: Group 2 (IIA) - 2 valence electrons
Transition Metals: Groups 3-12 - d and f block metals have 2 valence electrons
Boron Group or Earth Metals: Group 13 (IIIA) - 3 valence electrons
Carbon Group or Tetrels: - Group 14 (IVA) - 4 valence electrons
Nitrogen Group or Pnictogens: - Group 15 (VA) - 5 valence electrons
Oxygen Group or Chalcogens: - Group 16 (VIA) - 6 valence electrons
Halogens: - Group 17 (VIIA) - 7 valence electrons
Noble Gases: - Group 18 (VIIIA) - 8 valence electrons
What is the first group of the periodic table called?
Alkali metals
What are the characteristics of alkali metals?
- Soft (in comparison, alkaline earth metals are slightly harder than Alkali metals)
- Shiny
- Silver
Metals are insoluble in water or organic solvents, unless they undergo a reaction with them. Typically, this is an oxidation reaction that robs the metal atoms of their itinerant electrons, destroying the metallic bonding.
What are alkali metals very reactive with?
Water. For example sodium and water produce an explosion and hydrogen gas is a product.
Also they react commonly with Halogens to make ionic compounds. For example sodium chloride is table salt.
What do alkali metal compounds tend to look like?
White solids
What are chemical compounds?
A combination of two or more elements combined in a specific ratio
What is the second group of the periodic table?
Alkaline Earth metal
What are the physical characteristics of alkaline earth metals?
- Shiny
- Silver
- Kind of soft
- Not very soluble in water
What is the non-reactive group of elements called?
Noble gases
Where are the noble gases located on the periodic table?
The very last column on the right.
What are some characteristics of noble gases?
- Non-reactive
- Not dense
- Non-flammable
Why are noble gases unable to combust?
They are not reactive since they already have a full outer shell of electrons. Combustion is a chemical reaction so noble gases cannot combust.
What group is adjacent (to the left) of the noble gases?
Halogens
What are the characteristics of halogens?
- Poisonous
- Reactive with alkali metals
What are the three kinds of subatomic particles?
- Electrons
- Protons
- Neutrons
What are neutrons?
Neutral particles that add mass
What are electrons?
Negatively charged particles with so little mass that they are said to have no mass
What are protons?
Positively charged particles
Where are the protons and neutrons located?
The nucleus; so the protons and neutrons are called nucleons
What are energy levels of an atom?
A region of space near the nucleus that may be empty or contain electrons
How do you know the energy of electrons?
- Electrons further away from the nucleus have more energy
- Electrons closest to the nucleus have less energy
When electrons change position they can emit light which helps to see their energy level.
Why are electrons closest to the nucleus held tightly?
Because they are closest to protons and the opposite charges attract each other.
What is the organization of the levels of electrons?
2, 8, 8, 18, 18, 32, 32
Find this by counting the amount of elements in each row of the periodic table
(There is more to learn here later about the organization of the electrons but this knowledge is sufficient for grade 10; you only need to memorize the first four rows)
How do elements bond? Explain what the electrons do.
There are two main types of bonding, with a grey area in between.
Covalent/molecular bonding:
Partly filled energy levels from two different atoms can overlap and electrons can exist in both of them at once. This is called covalent bonding or molecular bonding. The result is a molecule. Two or more non-metals will form a covalent bond.
Ionic bonding:
Also, ionic bonds can occur. This is where one element steals one or more electrons from another element and then the resulting ions carry opposite charges making them stick to each other due to their opposite charges. A common example of an ionic bond is NaCl which is table salt. The sodium gives away an electron to the chlorine so that they can each have an outer shell that resembles that of the closest noble gas. Ionic bonds involve one metal element (duplicates of this metal are allowed).
What does the atomic number tell you?
The number of protons an element has
What are isotopes?
Atoms of the same element that contain different numbers of neutrons
What is heavy hydrogen?
An isotope of hydrogen that contains 1 neutron, since usually hydrogen would just have one proton and one electron, it is heavier when it also has the neutron. Look at the atomic mass number of hydrogen and you will see that it is common to not have the neutron.
What does the mass number tell you?
The amount of protons and neutrons (the number of nucleons) in an atom
How can the atomic symbol of an element be represented without being in the periodic table
- Mass number (top left)
- Element symbol (right)
- Atomic number (bottom left)
This is the nuclear model of the atom
What is the atomic mass (also known as the atomic molar mass)?
The average mass of the isotopes of an element (so notice that the amount of neutrons can change and it is still the same element)
What is ionization?
When elements gain or lose electrons
What is an ion?
An unbalanced or electrically charged atom (it does this to achieve an outer shell like the nearest noble gas)
What does ionization create? What sections of the periodic table participate in this type of compound?
Metals and non-metals form ionic compounds
What are cations?
Positively charged atoms that form when atoms lose electrons represented by 1+ or 2+ etc.
Notice that the positive sign goes after the number.
What are anions?
Negatively charged atoms that form when atoms gain electrons represented by 1- or 2- etc.
Notice that the negative sign goes after the number.
Why do atoms gain and lose electrons?
So they can become stable like noble gasses creating full outer shells of electrons
What are valence electrons?
The electrons in the outer energy layer of an atom
What does valence mean?
The tendency to gain or lose electrons
What is the octet rule?
When atoms bond in such a way that they are able to have 8 electrons in their outer layer