17) 8.4 / 20 x 100
18) 20 . 0.5150
19) 6,50% because (as you said) the law of definite proportions states that regardless of the amount, a compound is always composed of the same elements in the same proportion by mass
Answer:double displacement
Explanation:I just did it
Exothermic releases energy(heat) from the system to the surrounding
endothermic takes energy (heat) from the surrounding to the system
<span>As the Sun sets, the moon rises with the tide that faces the
Earth fully exposed to sunlight. The moon has phases because of its orbit to
Earth which causes the portion we see illuminated to change. The new moon
occurs when the moon is positioned
between the earth and the sun. at full moon and third quarter or called
as the half moon, it happens when the moon is at a 90 degree angle with respect
to the earth and the sun. crescent refers to the moon that is less than half
illuminated by the sun. gibbous refers to more than half illuminated by the
sun. waxing means growing or expanding in illumination and waning means
shrinking or decreasing in illumination.</span>
