group 18

What are the elements in group 18 (the far right) of the periodic table called?

• Alkali metals

• Alkaline earth metals

• Halogens

• Noble gases

Diagram shows the symbol of neon. Which statements is not true about neon?

• Neon exist as a monatomic elements

• Neon has low melting and boiling point

• Neon has a low density

• Neon reacts with bromine to form a covalent compound

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Which property of Group 18 elements increases when going down the Group in the Periodic Table?

• Forces of attraction

• Reactivity

• Solubility in water

• Electrical conductivity

The symbol for helium is

• H

• He

• Hl

• Hm

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The symbol for argon is

• Ar

• Ag

• An

• A

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Helium is a good insulator. Why?

• Helium do not contains mobile ions

• Helium do not contains mobile electrons

• Helium is not inert

• Helium is light

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Why is Helium used in divers' tank but not hydrogen gas?

• Helium is lighter than hydrogen

• Helium is inert to any chemical reactions

• Helium is cheaper

• Helium is easy to get from market

Argon (proton number =18) is inert to any chemical reaction because

• It is light

• it is located in Group 18

• it has achieved stable duplet electron arrangement

• it has achieved stable octet electron arrangement

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Dimitri Mendeleev's classification of the elements in the Periodic Table was a great improvement compared to John Newlands because

i He left gaps to be allocated for undiscovered elements

ii He predicted the properties of the undiscovered elements

iii He classified the elements into triads

iv He arranged the elements in ascending order of their proton numbers.

• i and ii are correct only

• i and iv are correct only

• ii and iii are correct only

• iii and iv are correct only

The following shows some information about element Q.

1) Relative atomic mass is 9

2) has 5 neutrons

Which statements is correct about element Q?

• Element Q is placed in Group 15 of the Periodic Table

• Atom Q has 9 protons

• Element Q has 2 valence electrons

• Atom Q has three shells occupied with electrons