Answer:
The correct answer is D circulatory system.
Explanation:
Blood is the principle component of circulatory system.Red blood cells contain hemoglobin protein that transport oxygen throughout the body.
Thus circulatory system works together with the cardiovascular system to move red blood cells containing oxygen throughout the body.
Answer:
copper oxide has been reuced into copper
Explanation:
The copper has gained electrons to become stable on its own without oxygen
OILRIG- show that reducution is the gain of electrons
Answer:
0.268 L
Explanation:
concentration is the number of moles of solute in 1 L of solution
number of moles of KCl - 5.0 g / 74.5 g/mol = 0.067 mol
the concentration of the solution to be prepared - 0.25 mol/L
concentration = number of moles of KCl / volume of solution
substituting the values in the equation
0.25 mol/L = 0.067 mol / V
V = 0.268 L
solution should be diluted to 268 mL to make a 0.25 M solution