1. horizontal row in the periodic 2. vertical column in the periodic 3. a repetition of properties occurs when elements are arranged in order of increasing atomic 4. type of element that is a good conductor of heat and electric 5. type of element characterized by the presence of electrons in the 6. one-half the distance between the nuclei of two atoms when the atoms are 7. type of ion formed by group 2a 8. subatomic particles that are transferred to form positive and negative 9. ability of an atom to attract electrons when the atom is in a 10. energy required to remove an electron from an atom

1. Periods

2. Groups of families

3. the statement is true about Periodic law

4. metals

5.transition metals

6.atomic radius

7. cations

8. electrons

9. electronegativity of the atom

10. ionization energy

Explanation:

1. horizontal row in the periodic tableare called Periods

2. vertical column in the periodic table are called Groups of families

3. A repetition of properties occurs when elements are arranged in order of increasing atomic number. True about Periodic Law (most elements that fall within the same families has similar properties)

4. type of element that is a good conductor of heat and electric current are metals that are found in group 1 and 2 of the periodic table Boron, tin, silver, Zinc, Alluminium, Germanium, Pollonium, antimony, e.t.c

5. type of element characterized by the presence of electrons in the dorbitalare called transition metals

6. one-half the distance between the nuclei of two atoms when the atoms are joined are called atomic radius

7. type of ion formed by Group 2A elementsare Cations

8. subatomic particles that are transferred to form positive and negative ions are called electrons

9. ability of an atom to attract electrons when the atom is in a compound is called electronegativity of the atom

10. energy required to remove an electron from an atom is called ionization energy

spectral lines lyman is one set