Periods

Question 1

Dimitri Mendeleev and lathar Meyer

Answer 1

Triads

Question 2

Triads

Answer 2

3 similar elements 
Atomic weight equal average of the atomic weights of the other two 
Chlorine bromine iodine 
Calcium strontium barium 
Sulfur selenium tellurium

Question 3

First classification according to

Answer 3

Atomic weight

Question 4

Law of octaves

Answer 4

English chemist JAR

Increasing of atomic weight with similar properties after each 7 elements

Question 5

Newlands

Answer 5

Fist to detect a periodic pattern
Participated developments of the periodic table
Law of octave

Question 6

Mendeleev

Answer 6

Predicted the discovery of germanium (eka-silicon) between zinc and arsenic similar to silicon

Question 7

Modern periodic table

Answer 7

1913
Henry Moseley
Wavelength of X Ray spectral lines of number of elements
Ordered of X Ray emissions (atomic number)

Question 8

Discovery of isotopes

Answer 8

No to atomic weight

Increasing of atomic number

Question 9

Periodic trends

Answer 9

Sizes of atoms and ions 
Ionization energy 
Electron affinity 
Electronegativity 
Metallic character

Question 10

Effective nuclear charge

Answer 10

Atom and electron attracted to the nucleus and repelled by the other electrons

Question 11

Two factors that depends the nuclear charge

Answer 11

Zeff=Z-S
Z atomic number
S screen constant close to the number of inner electrons

Question 12

Size of atom

Answer 12

Bonding atomic radius

Radius: one half of the distance between covalent oh bonded nuclei

Question 13

Ionic size depends

Answer 13

Nuclear charge
Number of electrons
Orbitals in which electrons reside

Question 14

Cations are smaller than their parent atoms

Answer 14

Outermost electron is removed and repulsions are reduced

Question 15

Anions are larger than their parent atoms

Answer 15

Electrons are added ad repulsions are increased

Question 16

Ions increase in size as you go down a column

Answer 16

Due to the increasing value of n

Question 17

Isle letting series

Answer 17

Ions have the same number of electrons

Question 18

Ionic size decreases with

Answer 18

An increasing nuclear charge

Question 19

Ionization energy

Answer 19

Amour of energy required to remove an electron from the ground state of a gaseous atom or ion

Question 20

It requires more energy to remove each successive electron

Answer 20

When all valence electrons have been removed

The ionization energy takes a quantum leap

Question 21

Electron affinity

Answer 21

The energy change that occurs when an electron is added to a gaseous atom or ion

Question 22

Electro negativity

Answer 22

Attract electrons to itself

Question 23

Metal or nonmetal

cation or anion

Answer 23

Metal cation

Nonmetal anion

Question 24

N

Answer 24

Atómica mass