Answer : Yes, a precipitate form when a solution of calcium chloride and a solution of mercury(I) nitrate are mixed together.
The net ionic equation will be,

Explanation :
In the net ionic equations, we are not include the spectator ions in the equations.
Spectator ions : The ions present on reactant and product side which do not participate in a reactions. The same ions present on both the sides.
The given balanced ionic equation will be,

The ionic equation in separated aqueous solution will be,

In this equation,
are the spectator ions.
By removing the spectator ions from the balanced ionic equation, we get the net ionic equation.
The net ionic equation will be,

A.
Weldings sparks could start fire on wood.
Lightning can ignite a fire one a tall tree
Open flames can start another fire if made in contact especially with flammable substances
Answer:
the third option
Explanation:
The circuit is incomplete and broken, and the lights in the circuit do not shine.
An open circuit means an incomplete circuit.
The first option is wrong since the lights do not shine in an open circuit.
The second option is wrong since an open circuit is incomplete.
The fourth option is also wrong since an open circuit is broken or incomplete.
∴ The third option is correct.
Insects and dogs are both in the Animalia classification.