It is important to establish the true weight of the crucible because it is a necessary reference point. Later, you will be weighing the crucible to determine how much of the products are present, so it's necessary to have the true tare weight of the crucible.
<span>The crucible is heated to be sure it is free of any moisture or other volatiles that might otherwise give a misleading weight. If you start out with the crucible absolutely clean and dry, (after heating) then you know that any additional weight must have come from the sample.</span>
Answer:
The answer should be, B, The periodic table
Carbon dioxide and h20 or carbon dioxide and sunlight
“Electronegativity is a measure of the tendency of an atom to attract a bonding pair of electrons.”
https://www.chemguide.co.uk/atoms/bonding/electroneg.html
^this link may help you understand. Good luck!
Answer:
electron revolving in a shell is associated with a definite amount of energy. The energy changes when it jumps to another shell that is so say when it goes from one level of energy level to another. Thus shell also gives the energy of a electron besides its location and are therefore called energy levels.