Section 1.2 Q-cards Flashcards
Study for the unit test. its not a unit test tho its just 1.2 1.3 2.1 (28 cards)
By the mid-1800s, how many elements were known to exist?
By the mid-1800s, about 63 elements were known to exist.
What is the history of the Periodic Table chronologically?(People)
John Newlands
Demitri Mendeleev
Henry Moseley
Who is John Newlands?
An English chemist who discovered that 56 elements should be classified into 11 groups that have similar chemical properties.
He notices the change in atomic mass differed in each group by a factor of 8.
Who is Dmitri Mendeleev?
A Russian chemist and teacher arranged elements in increasing order of atomic mass to make the periodic table.
Mendeleev left a blank for yet-undiscovered elements. He had made good predictions
Who is Henry Moseley?
A British physicist arranged elements according to increasing atomic number - the arrangement we use today.
Periodic Law, what is it?
It states that elements arranged in order of increasing atomic number and chemical and physical properties are repeted every period.
Group?
A column in the periodic table. The elements in each group have similar traits, bonding properties, and electron arrangement. elements can be categorized as:
Alkali metals
Alkaline Earth metals
Halogens
Noble Gases
Number of valence electrons is completely predictable from the group number, except for the elements in group 12.
Period?
It is a row in the periodic table.
Incresing atomic number from left to right.
Why do elements have similar properties?
Because of there’s valence electrions.
What are the properties of metals?
Solid at room temperature with the exception of mercury
Tend to be shiny
Good conductors of electricity
Malleable and ductile
What are the properties of non-metals?
**Solid **at room temperature
Some are gases
Only Bromine is liquid among non-metals
Not shiny, Doesn’t conduct electricity
Non-malleable or ductile
What are the properties of Metalloids?
Their properties is between metal and non-metal
Brittle and often poor conductors of electricity
Boron is the start of the ‘W
Main groups?
Groups 1,2, and 13 through 18 are the main-group elements they are the most prevalent elements on earth.
Transition Elements?
The center of the table contains the transition element - sometimes called the transition metals.
Can have up to 18 electrons in their outer shell.
Their electron configurations are more complex than those of the main-group elements in the periodic table.
Inner Transition Elements?
Inner transition elements lie at the bottom of the table.
Period 6 reads “La-Lu” meaning that all of the elements from lanthanum through lutetium belong there. Period 7 reads “Ac-Lr” indicating the location of the elements from actinium through lawrencium.
They can have as many as 32 electrons in some of their valence shells.
Alkali metals?
Group 1 (except hydrogen)
Very reactive with water
Alkaline earth metals?
Group 2
Still reactive
Other metals?
Group 12 and Under the metalloids
shiny solids but this time they don’t conducte electrisity.
Other non-metals?
Everything above the metalloids.
not halogens or noble gases. They in between
They are very common elements in the tissues of living organisms.
Noble Gases?
Group 18
Not reactive cuz they are full valence
Halogens?
Group 17
They are reactive nonmetals
Lanthonoids?
Period 6
sometimes called rare earth metals cuz they were rare.
Batterys and hybird cars.
Actonoids?
Period 7
no stable isotopes (so they are radioactive😔)
Reactivity of Elements?
The degree to which an element reacts with another depends on the electron arrangement of the atom.
The general trends are
Main group metals: reactivity increases down the group
Non-metals: reactivity increases up the group.
Reactivity is greater to the far left and right of the periodic table.
