Answer:
b) 2.0 mol
Explanation:
Given data:
Number of moles of Ca needed = ?
Number of moles of water present = 4.0 mol
Solution:
Chemical equation:
Ca + 2H₂O → Ca(OH)₂ + H₂
now we will compare the moles of Ca and H₂O .
H₂O : Ca
2 : 1
4.0 : 1/2×4.0 = 2.0 mol
Thus, 2 moles of Ca are needed.
Answer:
Newton's First Law states that an object in motion will stay in motion, an object at rest will stay at rest, at a constant velocity, unless an unbalanced force acts upon it.
Newtons First law of motion has to do with seat belts because think about it, what happens when we don't wear a seat belt and our vehicle comes to a quick stop. What happens to you? You move forward and stay in motion until an unbalanced force acts upon you. Now what is an unbalanced force? An unbalanced force is one that is not opposed by an equal and opposite force operating directly against the force intended to cause a change in the object's state of motion or rest. So, when you come to a stop, you wouldn't stop motion unless a force is caused to change your motion and put you at rest. If you were wearing a seat belt, the seat belt would act as the unbalanced force, it would stop you from being in motion.
Answer:
3 because it the element that combined the form
Answer:
they get colder and darker, with less light
Explanation:
