C. The neutron number.
An element is determined based on how many protons has, if the protons number change then you got a new element.
If the number of neuron change you got the same element except it will be a bit heavier or lighter if you are gaining or loosing neutrons. Those variations of an element are called the isotops of the element.
The protons and neutrons toghether form the nucleus of the atom that is heavy and dense as an elephant.
The electrons are light as fleas and stay on the shels of around the nucleus and if they are more then the number of protons they make the atom negatively charged and vice versa.
Answer: The pressure of a gas will increase when there is a decrease in the volume of the gas.
Explanation: according to Boyle's law, the volume of a gas will decrease when the pressure is increased at constant temperature and vice versa.
No, because humans are much more complex than peas.
Answer:
<h3>The answer is 8.29 %</h3>
Explanation:
The percentage error of a certain measurement can be found by using the formula

From the question
actual density = 19.30g/L
error = 20.9 - 19.3 = 1.6
We have

We have the final answer as
<h3>8.29 %</h3>
Hope this helps you
Answer: The correct option is B.
Explanation: To describe the motion of an object, we use the equations of motion.



From the above equations, we require position, speed and direction through which we an calculate the displacement, velocity and acceleration.
To calculate the complete motion of an object, we require all the three factors.
Hence, the correct option is B.