The answer is A because Ag and Cu switch places- a SINGLE change occurred :) hope this helped!!
Each carbon atom has 4 elections available for bonding. One of 2 of these are used for the C - C bond so there are 6 available to bond with hydrogen. So maximum number of hydrogen atoms = 6.
The percent composition of W in WC is 93.868 %.
MM of WC = 183.84 u + 12.01 u = 195.85 u
% W = Mass of W/Mass of WC × 100 % = 183.84 u/195.85 u × 100 %
= 93.868 %.
<span>The independent variable is the one that does not change depending on other variables - so here it would be the presence or the absence of caffeine - this is dependent on Tina's actions, but not on other variables in the experiment. The dependent variable is the heart rate - it is assumed to depend on the presence or absence of caffeine. A hypothesis could be that "Caffeine causes an increase of heart rate in earthworms" - and this hypothesis is what the experiment is testing.</span>
