This demonstration is most likely trying to show you potential energy. The rock is heavier than the pebble and will therefore displace more sand upon impact showing that the rock stores more potential energy than the pebble does when they are elevated to the same height (in this case the height is the height of the table).
This makes sense since potential energy is equal to mass times the acceleration due to gravity times height (PE=mgh) and the only thing that is changing is the mass of the object being suspended which means that the heavier object (the rock) will have more potential energy.
I hope this helps. Let me know if anything is unclear.
The correct answer is answer choice B, 2. Calcium is in Column 2, meaning that it has 2 electrons in its outermost energy level. These two electrons must be lost for it to form an ionic bond with another element and become stable.
Questions like these can be easily answered if you have a periodic table on hand. Elements in Column 1 need to lose 1 electron to form ionic bonds, elements in Column 2 need to lose 2, and so on. Keep in mind, however, that elements in the center of the table are more likely to form metallic or covalent bonds, and elements in Columns 16 and 17 need to gain 2 and 1 electrons, respectively.
Answer: When you put a hot object in contact with a cold one it heat will flow from the warmer to the cooler. and as a result the warmer one will be usually cool down and the cooler one will usually warm up. Eventually, they will reach the same temperature and heat flow will stop.
Explanation: Hope this helps
