The second statement is false. The Sun is a star, but not the only star.
Picking up a box, pushing a box along the ground, and pulling a box along the ground (B, C, and D) definitely involve work being done.
If a person CARRIES a box from one place to another, AND keeps it at the same height during the entire carry, then no work is done. ( A )
Answer:
(A) because there are the same number of atoms of each element shown on both sides
Explanation:
The Law of conservation of mass says that in a reaction the matter of the products should be equivalent to the matter of the reactants and the mass of the system should remain constant over time.
In a chemical reaction, while atoms bond is breaking of 1 substance than new bonds are formed in another substance and new substances are formed. However, in the overall reaction, they keep the same elements, no new elements can go and come from the outside. For example:
HCl + NaOH -----> NaCl + H2O
In this reaction, on both sides the same number of atoms of each element are present.
