Elements - A pure substance that cannot be broken down into simpler substances by physical or chemical means.
Alkali metals - naturally exist as compounds with other elements since they are very reactive low densities and melting points
Alkaline earth metals - highly reactive, exist as solids but are relatively harder than alkali metals, shiny, lustrous,
strongly conduct heat and electricity, denser and have higher boiling and melting points compared to Group 1
Transition metals - Hard, shiny and lustrous solids, High thermal and electrical conductivity; high melting points, often take on multiple charged states
Boron Family (Earth Metals) - usually hard, brittle, and have a low melting point. They are also good electrical and thermal conductors.
Carbon Family (Tetrels) - have much higher melting points and boiling points than the group 13 elements.
Nitrogen Family (Pnictogens) - may be transparent, either diamagnetic or paramagnetic at room temperature,
and may conduct electricity when heated
Oxygen Family(Chalcogens) - contains non-metals and metalloids. Many of these elements at high concentrations are toxic or damaging.
Halogens - nonmetallic elements that are highly reactive in nature react violently, particularly with metals, poor conductors of heat and electricity, low boiling and melting points
Noble Gases - colorless, odorless and nonflammable under standard conditions, most stable elements referred to as inert gases because of the initial notion that they were not at all reactive, least reactive nonmetallic gases
How are the elements arranged in the Periodic Table?
➢ Seven (7) horizontal rows called periods
○ A horizontal row in the periodic table is a period.
○ Periods are numbered 1 to 7, from top to bottom.
○ The period number states how many Energy Levels an element has.
➢ Eighteen (18) vertical columns called groups or families.
○ A vertical column in the periodic table is a group.
○ Groups are numbered 1 to 18, from left to right.
○ A group is also called a family because the elements in a group tend to have very similar physical and chemical properties.
○ The group number states how many Valence Electrons an element has
● Atomic number - number of protons in the atom’s nucleus
● Symbol - is used as a shorthand and in chemical equations
● Mass number - is the number of protons and neutrons in the nucleus of an atom.
o Metals – An element that is normally solid at room temperature with the exception of mercury (Hg)
✔ Metals are measured of the ease at which an electric charge or heat can pass through a material
✔ Metals have an ability to be hammered or rolled into thin sheets
✔ Metals have an ability to be stretched into thin wires
o Nonmetals - an element that does not have the properties of a metal. They can exist in solid, liquid, or gaseous
form.
✔ Non-metals are brittle.
✔ Non-metals are bad conductors of heat and electricity (except graphite).
✔ Non-metals are non-lustrous (dull) and cannot be polished (except iodine).
✔ Non-metals may be solids, liquids or gases at room temperature.
✔ Non-metals are neither tough nor strong.
o Metalloids -An element that has physical and chemical properties of both metal and nonmetal.
✔ Metalloids can conduct electricity but not as well as metals
✔ Metalloids are shiny but brittle and chips easily like glass.
✔ Metalloids are shiny like a metal but brittle like a nonmetal
✔ Metalloids are somewhat shiny and conducts electricity like a metal but brittle like a nonmetal
Classification of Elements
Group 1- alakali metals > very reactive, low densities, low melting points
Group 2- alkaline earth metals- highly reactive, good conductor of heat and electricity
group 3-12 transition metal > hard, shiny solids, thermal, high melting points
Group 13 boron family > hard, brittle, low melting point
Group 14- Carbon Family > high melting points and boiling points
Group 15 Nitrogen Family> transparent, conduct electricity when heated, can be either diamagnetic or paramagnetic at a room temperature
Group 16 Oxygen Family> nonmetals/metalloids
Group 17 Halogens > react violently with metals, poor conductors of heat electricity (insulators)
Group 18 Noble Gas > colorless, odorless, nonflammable (stable)
What is the defining characteristic of alkali metals?- existence as compounds with other elements
Which family of elements is known for its shiny, lustrous appearance and strong conductivity of heat and electricity? -Transition metals
Which group of elements typically exhibits multiple charged states and high thermal conductivity?- transition metals
Which element family is characterized by hardness, brittleness, and low melting points?- Boron Family
What property distinguishes halogens from other element groups?- high reactivity
Which group of elements is often referred to as inert gases due to their low reactivity?- noble gases
What is the primary characteristic of elements in the carbon family?- high melting points
What is the primary characteristic of elements in the nitrogen family?- good electrical conductivity
Which element family is known for its high reactivity and existence as compounds with other elements?- Alkali metals
Which group of elements has the highest reactivity and tends to react violently with metals?- Halogens
Which element family is characterized by its low boiling and melting points and poor conductivity?- halogens
if the atom is neutral or if its in element form: the number of protons is equal to electrons