15. D is correct, exothermic reactions release heat
I am not sure about 16
A bright feild is most commonly used
Density is not a chemical property. It is a physical property.Electromotive force, Flammability and pH are chemical properties.
Answer:
C. Scientists accepted the model at first but later rejected it.
Explanation:
Scientists accepted the model at first because it explained the hydrogen emission spectrum.
However, with the development of quantum mechanics, scientists had to modify the model (not reject it).
Electrons still had specific energies, but they no longer travelled in fixed orbits.
Instead, electrons had a probability of being found in a given region of space.
Answer:
Option b is show the chemical property of sodium....
