Oquizy

Which of the following substances contains only covalent bonds in its entire structure?

Magnesium chloride Silicon dioxide Sodium Water

Why do solid ionic compounds not conduct electricity?

The ions are fixed and cannot move Their electrons are not free to move They contain no charged particles They contain only molecules

What happens to electrons when two hydrogen atoms form a covalent bond?

Each atom gives away one electron One atom transfers both electrons to the other The atoms form ions and attract each other The two atoms share one pair of electrons

Why is graphite soft and slippery?

It contains free electrons It has a high density Its atoms are not strongly bonded The layers can slide over each other

Which statement best explains why alloys are harder than pure metals?

Alloys contain more protons than metals Alloys have more electrons The atoms are arranged in a perfect pattern The atoms are of different sizes, making it harder for layers to slide

The melting point of sodium chloride is higher than that of water. Why?

Ionic bonds are stronger than hydrogen bonds Sodium chloride contains molecules Sodium chloride is lighter Water contains more atoms

Why does graphite conduct electricity but diamond does not?

Diamond has a sea of electrons Diamond has more bonds Graphite has delocalised electrons Graphite has ions

Why do ionic compounds have high melting points?

Their electrons are free to move They are light They contain large atoms They contain strong electrostatic forces between ions

Which option best shows the formation of a covalent bond between two oxygen atoms?

One oxygen giving two electrons to the other Two oxygen atoms giving one electron to each other Two oxygen atoms sharing one electron Two oxygen atoms sharing two pairs of electrons

Xinyi draws a dot-and-cross diagram for NaCl. What is correct about electron movement?

Sodium and chlorine form a double bond Sodium gains one electron from chlorine Sodium gives one electron to chlorine Sodium shares electrons with chlorine

Why do simple molecular substances like CO₂ have low melting points?

Their molecules are light They contain ions They have weak covalent bonds They have weak intermolecular forces

Why are metals malleable?

Their atoms are soft Their bonds are weak Their layers of ions can slide over one another They contain molecules that bend

Quiz: Chemistry - Chemical Bonding