Vocab
define valence electrons
an atom's outermost electrons
Vertical columns on the periodic table are called families or what?
groups
What is the name for the group of elements belonging to group 17 (7A) that are extremely reactive nonmetals? List 3 elements in this group.
halogens; fluorine, chlorine, bromine, iodine, astitine
In general, are the nonmetals found to the right or left of the periodic table?
Right (mostly top right)
What is one thing elements in the same group have in common?
same number of valence electrons; similar chemical and physical properties
This group on the periodic table is considered the least reactive.
Noble gases
These substances have properties of both metals and nonmetals, and form a stairstep line on the periodic table dividing the metals from the nonmetals
metalloids
What is the name for the group of elements belonging to group 1A? Are these elements metals, nonmetals, or metalloids?
alkali metals besides hydrogen- metals, but hydrogen is a nonmetal
How can someone determine the number of valence electrons in an atom for main group elements?
group number = number of valence electrons
group 1A has 1 valence electron, group 7A (17) has 7 valence electrons
Elements on the periodic table are in order of increasing what?
atomic number/number of protons
Horizontal rows on the periodic table are called what?
Which rule states that atoms are most stable with a valence shell of 8 electrons?
octet rule
Name 2 alkaline earth metals.
magnesium, calcium, strontium, barium, radium, beryllium
Which type of substance makes up most of the periodic table, metals, metalloids, or nonmetals?
metals
How many valence electrons does sulfur have?
6 (group 16 or 6A)
These substances are excellent conductors of heat and electricity, and are usually malleable, ductile, and shiny.
metals
What does the number of valence electrons an atom has determine?
how it behaves (chemical properties), how it looks (physical properties)
How many valence electrons do the halogens have?
7 valence electrons
The two rows below the periodic table are called the lanthanide series and the actinide series. What is another name for them? Are they metals, nonmetals, or metalloids?
inner transition metals?
Which group is the least reactive- halogens (group 7A), alkali metals (group 1A), or alkaline earth metals (group 2A)? Why?
alkaline earth metals, they are the furthest away from a full valence shell of 8 electrons- 1A can lose one, 7A can gain one, but 2A has to lose 2
The periodic law states that the chemical and physical properties of an element are a repeating function of what?
atomic number (number of protons)
These substances are generally either brittle solids or gases at room temperature, and are poor conductors.
nonmetals
Why is it only common to predict the number of valence electrons for atoms in groups 1-2 and groups 13-18? Why do we leave out the transition metals?
The transition metals have varying oxidation states due to their valence electrons not always being in the outermost energy level
Why does atomic radius decrease moving left to right across a period on the periodic table?
Elements on the right side of the periodic table tend to _______ electrons to form negative ions, while elements on the left side of the table tend to _______ electrons to form positive ions.
gain; lose