Answer:
<u>Chemical changes</u> are recognized when a substance changes its properties permanently and it cannot be the same substance as before.
Instead the<u> physical changes</u><u> </u>implies that if you can return to the same substance through a reverse process.
Explanation:
A chemical change is, by example, a combustion, if a sheet of paper burns, its result is ashes, the ashes cannot go back to being a sheet of paper because its properties changed, heat energy was generated that changed matter permanently.
A physical change, by example, is that of freezing water, the water becomes ice, but this can easily become water again if the temperature is increased, its properties do not change and the chemistry of the substance does not change.
Answer:
The centripetal acceleration changed by a factor of 0.5
Explanation:
Given;
first radius of the horizontal circle, r₁ = 500 m
speed of the airplane, v = 150 m/s
second radius of the airplane, r₂ = 1000 m
Centripetal acceleration is given as;

At constant speed, we will have;

a₂ = 0.5a₁
Therefore, the centripetal acceleration changed by a factor of 0.5
Answer:
-6 m/s^2
Explanation:
30 - 90 = -60
-60 / 10 = -6
If acceleration was constant, it will be -6 m/s^2
The answer to the question is sound
Answer:
John Dalton
Explanation:
Dalton's atomic theory was the foundation for a new understanding of chemical structures. He proposed that matter was constituted by indivisible and indestructible particles "atoms." He theorized that all atoms of a particular substance were equal, and the atoms of different substances had atoms of different sizes and masses.
He also proposed that all compounds of elements were combinations of elements but in a very precise ratio.