THE PERIODIC TABLE
The periodic table is the table that shows the arrangement of elements in the order of increasing atomic number.
The modern periodic law states that the properties of elements are a periodic function of their atomic number.
FEATURES OF THE PERIODIC TABLE
The modern form of the periodic table is divided into eight vertical columns known as GROUPS and seven horizontal rows known as PERIODS.
GROUPS: the vertical column of elements are numbered from I to VIII (or 0). Elements in the same group have the same number of valence electron in their outermost shell. Hydrogen can be placed in group I or group VII because it can donate its one electron like the group I element or accept electron like the group VII elements, But for convenience and because of its simple valence electron, it is placed in group I. In group VIII, that is group 0, Helium has two electrons while the other elements have eight valence electrons. There are also, the transition groups of elements. These lay between group Il and III in the periodic table.
PERIODS: The horizontal rows of elements or periods are numbered from 1 to 7. Elements in the same period have the same number of electron shells. Among the elements in period six and seven are the elements of Lanthanides and Actinides series knows as inner transition metals.
FAMILIES OF ELEMENTS
Elements in the same group may be said to belong to a family since they show similar properties because their atoms have the same number of valence electrons. At the same time, certain properties of the element in the same group show a gradual change with an increase in atomic number. Such gradual change of property within a group is known as GROUP TREND.
GROUP I: Lithium (Li), Sodium (Na), Potassium (K), Rubidium (Rb), Caesium (Cs), and Francium (Fr). Their properties are:
- They are univalent elements.
- They are good reducing agent since they can readily donate one electron to form cations.
- They are metals; thus, they are good conductors of electricity and heat.
- They react vigorously with cold water to liberate hydrogen gas and form alkali, hence, they are known as ALKALI METALS. Example
2Na(s) + 2H20(L) ——-> 2NaOH(aq) + H2(g)
GROUP II: Beryllium (Be), Magnesium (Mg), Calcium (Ca), Strontium (Sr), Barium (Ba), and Radium (Ra). Their properties are:
- They are divalent elements and are also known as alkaline earth metals.
- They ionize by donating their two valence electrons; hence they are good reducing agents.
- They are hard metals, ductile malleable and can conduct both electricity and heat.
- Beryllium does not react with cold water or steam, magnesium reacts with steam only while calcium reacts slowly with cold water to liberate hydrogen gas.
GROUP III: Boron (B), Aluminum (Al), Gallium (Ga), Indium (In) and Thallium (Tl). They are trivalent elements. Their properties are:
- They are reducing in nature since they can donate their three electrons to form electrovalent compounds.
- Only aluminium can react with steam at about750°C to liberate hydrogen gas.
- Oxide and hydroxide of aluminum is amphoteric in nature, i.e, they have both acidic and basic properties.
GROUP IV: Carbon (C), Silicon (Si), Germanium (Ge), tin (Sn) and lead (Pb). Their properties are:
- They form covalent compounds.
- They exhibit two oxidation states: +2 and +4. The +2 oxidation state becomes more prominent down the group.
- Electropositivity increases down the group.
- Carbon is a non-metal; silicon and germanium are metalloids while tin and lead are metals.
- Carbon does not react with water in any form, but silicon and tin react with steam at red heat.
GROUP V: Nitrogen (N), Phosphorus (P), Arsenic (As), Antimony (Sb) and Bismuth (Bi) belong to group V. Their properties are:
- They exhibit oxidation states of -3 and +5.
- They also show a group trend. Nitrogen and phosphorus are non-metals; arsenic and antimony are metalloids while bismuth is a metal.
- They are electron acceptors, hence they are oxidizing in nature. oxide.
GROUP VI: Oxygen (0), Sulphur (S), Selenium (Se), Tellurium (Te), and Polonium (Po). Their properties are:
- They are non-metals and exist as solids at room temperature except for oxygen
- They are electron acceptors and oxidizing in nature.
- They do not react with water in any form. But oxygen and sulphur combine directly with hydrogen to yield water and hydrogen sulphide respectively.
GROUP VII: Fluorine (F), Chlorine (Cl), Bromine (Br), lodine (I) and Astatine (At). They are known as halogens (salt-makers). Their properties include:
- They ionize to form univalent anions.
- They exist as diatomic molecules.
- As electron acceptor, all halogens are good oxidizing agents.
- They exhibit the following group trend. Fluorine and chlorine are gases, bromine is a liquid and iodine and astatine are solids at room temperature.
GROUP VIII (0): Helium (He), Neon (Ne), Argon (Ar), Krypton (Kr), Xenon (Xe) and Radon (Rn). The elements in group 0 are known as rare or noble gases because they are non-reactive and exist freely as monoatomic molecules in the atmosphere.
TRANSITION ELEMENTS
These are elements found in-between group II and III of the periodic table. The first transition series consists of elements: Scandium (Sc), Titanium (Ti), Vanadium (V), Chromium (Cr), Manganese (Mn), Iron (Fe), Cobalt (Co), Nickel (Ni), Copper (Cu) and Zinc (Zn). Transition elements have the following properties:
- High melting and boiling points
- Variable oxidation states
- Formation of coloured ions
- Formation of complex ions
- Catalytic ability
LANTHANIDES AND ACTINIDES
LANTHANIDES: These are found in period six. This series begins with Lanthanum (La) and ends with Lutetium (Lu). They are altogether 15 and resemble one another greatly.
ACTINIDES AND THE ARTIFICIAL ELEMENTS: The actinides are similar to the Lanthanides. They are found in the seventh period, which starts with Actinium (Ac) and ends with Lawrencium, (Lr). The famous Uranium is in this group. The elements with atomic numbers from 93 to 103 are known as artificial elements. This is because they do not occur naturally but were formed during nuclear reactions.
Lessons
HA’YHWH 🛐 YESHUA 🛐 HAMASCHIAC 🛐 SCHOOL SS3 HA’YHWH 🛐 YESHUA HAMASCHIAC 🛐 BIRTHDAY 🛐 – FIRST TERM, Chemistry, Lesson 1 WAEC
HA’YHWH 🛐 YESHUA 🛐 HAMASCHIAC 🛐 SCHOOL SS3 HA’YHWH 🛐 YESHUA HAMASCHIAC 🛐 BIRTHDAY 🛐 – FIRST TERM, Chemistry, Lesson 2 (Alkanes). WAEC
ALKANES Alkanes are a series of compounds that contain carbon and hydrogen atoms with single covalent bonds. These are known as saturated hydrocarbons. This group of compounds consists of carbon and hydrogen atoms with single covalent bonds. Also comprises a homologous series having a molecular formula of CnH2n+2 List of Alkanes and its Structures The list …. Read More
HA’YHWH 🛐 YESHUA 🛐 HAMASCHIAC 🛐 SCHOOL SS3 HA’YHWH 🛐 YESHUA HAMASCHIAC 🛐 BIRTHDAY 🛐 – FIRST TERM, Chemistry, Lesson 3(Alkenes). WAEC
ALKENES Alkenes are hydrocarbons with the formula CnH2n. Alkenes contain the C=C functional group. Alkenes are unsaturated and undergo addition reactions. ETHENE Ethene is a hydrocarbon which is denoted by a formula C2H4 or H2C=CH2. It is the simplest alkene and also the second simplest unsaturated hydrocarbon C2H2. Laboratory Preparation Preparation of ethene from ethanol. Ethanol …. Read More
HA’YHWH 🛐 YESHUA 🛐 HAMASCHIAC 🛐 SCHOOL SS3 HA’YHWH 🛐 YESHUA HAMASCHIAC 🛐 BIRTHDAY 🛐 – FIRST TERM, Chemistry, Lesson 4 (Alkynes). WAEC
ALKYNES Alkyne is an unsaturated hydrocarbon containing at least one carbon-carbon triple bond. The general formula of alkynes is CnH2n-2 and the triple bond is known as the ‘acetylenic bond’. Many alkynes have been found in nature. Ethyne Ethyne (C2H2) is the first member of the alkyne family, with two carbon atoms connected by a …. Read More
HA’YHWH 🛐 YESHUA 🛐 HAMASCHIAC 🛐 SCHOOL SS3 HA’YHWH 🛐 YESHUA HAMASCHIAC 🛐 BIRTHDAY 🛐 – FIRST TERM, Chemistry, Lesson 5 (Aromatic hydrocarbon, Benzene). WAEC
Aromatic Hydrocarbons The aromatic hydrocarbons are unsaturated hydrocarbons which have one or more planar six-carbon rings called benzene rings, to which hydrogen atoms are attached. Many aromatic hydrocarbons contain a benzene ring (also referred to as an aromatic ring). A few examples of aromatic hydrocarbons are provided below. It can be observed that all these …. Read More
HA’YHWH 🛐 YESHUA 🛐 HAMASCHIAC 🛐 SCHOOL SS3 HA’YHWH 🛐 YESHUA HAMASCHIAC 🛐 BIRTHDAY 🛐 – FIRST TERM, CHEMISTRY, Lesson 6 (Alkanols). WAEC
ALKANOLS Alkanols is a homologous series with general molecular formula of CnH2n+1OH or R-OH. The functional group in alkanols is the hydroxyl (-OH) group. NOMENCLATURE: The names of alkanols are obtained by substituting “e” in alkanes with “ol”. Example: Methanol – CH3OH, Ethanol – CH3CH2OH CLASSES OF ALKANOLS There are three classes of alkanols – …. Read More
HA’YHWH 🛐 YESHUA 🛐 HAMASCHIAC 🛐 SCHOOL SS3 HA’YHWH 🛐 YESHUA HAMASCHIAC 🛐 BIRTHDAY 🛐 – FIRST TERM, CHEMISTRY (Alkanoic Acids), Lesson 7. WAEC
ALKANOIC ACID (CARBOXYLIC ACIDS) Alkanoic acids have carboxylic group as their functional group i.e –COOH. The general molecular formular is CnH2n+1COOH. They occur in fats and oils. They are pepared in the laboratory by the oxidation of primary alkanols with excess acidified potassiumtetraoxomanganate (vii) The name of any alkanoic acid ends with –ioc 1. methanoic …. Read More
HA’YHWH 🛐 YESHUA 🛐 HAMASCHIAC 🛐 SCHOOL SS3 HA’YHWH 🛐 YESHUA HAMASCHIAC 🛐 BIRTHDAY 🛐 – FIRST TERM, CHEMISTRY, Lesson 8 (Fats and Oils as Higher Esters). WAEC
FATS AND OILS AS HIGHER ESTERS Fats and Oil • Oils and fats belong to a group of organic compounds known as lipids. • Oils and fats are natural occurring esters. • Fats are found in animals. • Oils are found in both animals and plants. • Fats and oils are esters (fatty acids + glycerol) • Fatty acids …. Read More
HA’YHWH 🛐YESHUA 🛐HA’YHWH 🛐HAMASCHIAC 🛐 SCHOOL, SS3 HA’YHWH 🛐YESHUA 🛐HAMASCHIAC 🛐PASSOVER 🛐RESURRECTION 🛐ASCENSION 🛐TERM, CHEMISTRY Lesson 1 (Radioactivity). WAEC
RADIOACTIVITY This is the spontaneous emission of radiation by radioactive element such as Thorium, Uranium etc. Characteristics Spontaneously and continually emitting of radiation by radioactive element Temperature and pressure have no effect on radioactivity The radiation can pass through opaque objects It affects photographic plates It causes ionization of gases through which it passes. It …. Read More
HA’YHWH 🛐YESHUA 🛐HA’YHWH 🛐HAMASCHIAC 🛐 SCHOOL, SS3 HA’YHWH 🛐YESHUA 🛐HAMASCHIAC 🛐PASSOVER 🛐RESURRECTION 🛐ASCENSION 🛐TERM, CHEMISTRY Lesson 2 (Nuclear Reactions). WAEC
NUCLEAR REACTIONS This is the spontaneous emission of radiation that involves the nuclei of radioactive element. Nuclear Fusion This is the process in which two or more light nuclei of elements combine together to form a heavier nucleus with release of both energy and radiation. This process is used to produce hydrogen bomb, it is …. Read More
