A) Ca, Mg, Be
The first ionization energy increases as we move up a group because of the smaller atomic size and less shielding of electrons.
C. carbon is the correct answer
To find out the answer, we must know the mass percentage of Cu in the mineral chalcopyrite.
Mass percentage of Cu = molar mass of Cu/molar mass of chalcopyrite = 64/(64+56+32*2) = 34.8%.
So to obtain 210 g pure Cu, the amount of mineral need = mass of Cu/mass percentage of Cu = 210 g/34.8% = 603 g = 0.603 kg.
Below are the choices:
<span>The independent variable is the number of dry cells, and the dependent variable is the length of time the bulb works.
</span><span>The independent variable is the length of time the bulb works, and the dependent variable is the number of dry cells.
</span><span>The independent variable is the number of dry cells, and the dependent variable is the amount of energy available.
</span><span>The independent variable is the amount of energy available, and the dependent variable is the number of dry cells.
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I think the answer is <span>The independent variable is the number of dry cells, and the dependent variable is the amount of energy available.</span>
A molecule is larger because it is a bond of atoms.
