Answer:
You will find the mass of the pan and water but if the water got to its boiling temperature that mass may be a little bit off seeing as some of it may have evaporated
H2O is a compound. So it's second one.
Answer:
Element 2
Explanation:
If we look at the model stated for element 1, it is clear that element 1 must be a noble gas. It has eight electrons in its outermost shell this implies that it has already attained a complete octet of electrons and is reluctant towards chemical reaction.
The second element belongs to group 16 since it has six electrons on its outermost shell. It is certainly more reactive than element 1 which is a noble gas.
Potassium is placed where it is based on its properties and it's reactivity. It's also placed there based on it's atomic number.
