Answer:
An elements atomic number will never change, that is because the atomic number is its "identity."
Answer:
this situation would not be physically possible
Answer:
Explanation:
According to Newton’s law of cooling, the rate of loss of heat from a body and the difference in the temperature of the body and its surroundings are proportional to each other.
Here, 
represents temperature at time t, R as the room temperature, t as the independent variable, y as the dependent variable.
Answer:
π/2 (90°)
Explanation:
The dot product of two vectors equals the product of their magnitudes and the cosine of the angle between them.
a·b = ||a|| ||b|| cos θ
If the dot product is 0:
0 = ||a|| ||b|| cos θ
0 = cos θ
θ = π/2
The angle between a and b is π/2 (90°).
