Answer:
Double Displacement Reaction
Explanation:
A double displacement reaction is a type of chemical reaction in which the reactant ions exchange places to form new products. Usually, a double displacement reaction results in precipitate formation.
Well, the cause of a volcanic eruption is when the lower crust melts. This leads to the formation of magma. The volcano is an opening through which the magma is discharged. The rock inside the earth melts. This magma is diffused upwards through the volcano. If magma reaches the top of the volcano, it behaviour depends on viscosity. So what happens before a volcanic eruption is that the lower crust melts, causing the formation of magma, which is released through the volcano. Hope i helped.
Answer:b.CaCl2
Explanation:
A compound is a substance resulting when two or more elements are are chemically bonded together either ionically or covalently in a fixed ratio.
From the given options we can see that the only compound there is CaCl2 which is an ionic compound in the fixed ratio of one calcium ion to two chloride ions.
Other options , Cu,Na and Nd are merely pure substance---Elements
The compound name for H3S5 is hydrosulfide sulfanide sulfide