If you look on the periodic table you will see the top group elements depending on how the elements relate to each in the column. All of the elements in that column show they all have 1 electron in their valence shell. Some of the chemicals in that family or group are Sodium, Lithium, Potassium. The are very reactive because they only have one electron and what 7 more to become stable.
The answer would be c because a surface wave travels between two different materials, like air and water.
Answer:
Gold is not used for making electric wires because it is too rare, and too costlier than Copper. Silver and copper are used for making wires. Copper is almost used in electric lines
Answer: When enough __energy__ is added to the substance, the solid reaches its _melting_ point and becomes a liquid
Explanation: since energy is being added the substance changes phase into a liquid .