Part 1
Mendeleev noticed that properties of elements usually repeated at regular intervals when
atomic mass
A horizontal row of blocks in the periodic table is called a(n)
period
How many elements are in a period in which only the s and p sublevels are filled?
8
Because the first energy level contains only the 1s sublevel, the number of elements in this period is
2
Moseley's work led to the realization that elements should be arranged by
atomic number
Elements in which the d-sublevel is being filled have the properties of
metals
Bromine belongs to group 17. How many electrons does bromine have in the outermost energy level
7
1/2 the distance between the nuclei of identical atoms that are bonded together is called the
atomic radius
The periodic law states that the physical and chemical properties of elements are periodic functions of their
atomic number
The group of 14 f block elements in the sixth period is the
lanthanides
What is the most electronegative atom on the periodic table?
fluorine
What is removed when the ionization energy is supplied to an atom of an element?
electron
Krypton is the 4th element in group 18. What is the atomic number of xenon, the 5th element?
54
What is the most reactive nonmetals on the periodic table?
halogens
The energy required to remove an electron from an atom is the atom's
ionization energy
A positive ion is called
cation
A measure of the ability of an atom in a chemical compound to attract electrons from another atom is
electronegativity
In a row in the periodic table, at the atomic number increase, the atomic radius
decreases
Which is the best reason that the atomic radius generally increases with atomic number in each group?
the number of occupied energy levels increases
The electrons available to be lost, gained, or shared when atoms form compounds are called
valence electrons