Answer:
B) a substance's color and odor changed Explanation: A signal that a chemical change has occurred is when its odor (its smell) or its appearance has changed.
The answer is 3/4.
The coefficient next to each reactant represents the amount of moles. The compound for oxygen is O2 and the compound for aluminum is 4. We can see that the number next to O2 is 3 and the number next to aluminum is 4.
To calculate number of moles, all you do is divide the given mass by the molecular molar mass:
<span>i.e. 125g / 18g = 6.94444g </span>
<span>Therefore, your answer is (a) 6.94 g</span>
D = m / V
0.736 = 225.0 / V
V = 225.0 / 0.736
V = 305.7 cm³
Answer: You would need 1 mole of Fluorine
Explanation:The equation is already balanced so just looking at the coefficients in the equation we can see that Sodium Chloride (2NaCl) needs two moles for this equation and fluorine (F2) only needs one.