Choose the correct answer: (Week 6 Test)

What is the molecular formula of a compound resulting from the combination of an element (X) from alkali metals with an element from halogens (Y)?

• YX₂

• YX

• X₂Y

• XY

The element whose atomic number is 17 forms a covalent bond with the element whose atomic number is __________.

• 1

• 11

• 12

• 13

An atom of element (A) from the fifth group is linked to three hydrogen atoms to form a compound with the formula __________ and the bond in the molecules is a __________.

• AH - single covalent

• HA3 - triple covalent

• HA - single covalent

• AH3 - single covalent

The number of bonds in a methane molecule is __________ single covalent bond(s).

• one

• two

• three

• four

Which of the following represents an ionic bond?

• H2O

• LiBr

• O2

An atom of element (X) binds to two hydrogen atoms. What type of bonding occurs in this molecule, and what is the group number of element (X) in the periodic table?

• Ionic - Group 6A

• Ionic - Group 2A

• Covalent - Group 6A

• Covalent - Group 2A

What is the symbol of the ion whose nucleus contains 27 nucleons, including 14 neutrons?

• Si+4

• Al+3

• Mg+2

• Na+1

An element from alkaline Earth metals forms an ionic bond with an element in group __________.

• 1A

• 2A

• 7A

• 0

The number of energy levels in a hydrogen positive ion is __________ the number of its atom.

• greater than

• less than

• equal to

• twice

When an atom turns into a positive ion, the number of electrons __________.

• decreases

• increases

• remains the same

• doubles