Answer:
D
Explanation:
A The calcium chloride dissolves in solution
B The mass of the solution totals 20 g
C The temperature of the solution is 35 degrees
D The solution became lighter in color
The correct answer would be that <u>the solution became lighter in color.</u>
An increase in temperature can also be considered a sign of a chemical reaction but in this case, the dissolution of calcium chloride in water is in itself exothermic.
A change in the mass of the final solution could also be considered a sign of a chemical reaction but in this case, the total mass equals the addition of the individual masses of the reactant.
The dissolution of calcium chloride in water is not enough as evidence of a chemical reaction. Dissolution can be a physical change of which, the evaporation of the water would retrieve the solute.
<em>A change in color, however, is one of the evidence to establish that a chemical reaction has occurred.</em>
The correct option is D.
Answer: When objects fall to the ground, gravity causes them to accelerate. Acceleration is a change in velocity, and velocity, in turn, is a measure of the speed and direction of motion. Gravity causes an object to fall toward the ground at a faster and faster velocity the longer the object falls.
Explanation:
Answer:
actually word equation has the names and we need to write molecular formula in chemical eqn. so I don't think there is sort of trick.You just need to memorise the molecular formula of chemicals.
Answer:
C
Explanation:
What causes blood pressure?
C
To pump blood around the body, the heart contracts and then relaxes through the cardiac cycle. The cycle begins with the contraction of the two atria, which push blood into the ventricles. Then, the ventricles contract, which forces the blood out of the heart.
When the heart pushes blood around the body during systole, the pressure placed on the vessels increases. This is called systolic pressure.
When the heart relaxes between beats and refills with blood, the blood pressure drops. This is called diastolic pressure.
