An atom is made up of three different particles, which are proton, neutron and electron. The proton and the neutron are located in the nucleus of the atom and they make up mass of the atom. The electron orbit around the nucleus. The proton is positively charged while the electron is negatively charged, thus, for the atom to remain neutral, the number of proton and electron in an atom must be equal. The neutron has no charge.
The atomic mass of an element = number of proton + number of neutron
Atomic mass of magnesium= 24
Number of proton = 12
Therefore, number of neutron = 24 - 12 = 12.
Thus, the number of neutron = 12.
Answer:
Please see below as the answer is self-explanatory.
Explanation:
- The visible range extends roughly from 400 nm (violet) to 700 nm (red).
- Below the violet is the ultra-violet spectrum (with higher energy) and above red, we have the infra-red spectrum.
- The wavelengths in the range of 650 to 690 nm have red as the dominant color.
Explanation:
15N in the north direction
The relationship between the frequency heard by the observer in motion and the original frequency of the sound is given by (Doppler effect)
where
f' is the frequency heard by the observer
v is the speed of the wave (the speed of sound)
is the speed of the source relative to the observer (= the speed of the car), and it is negative when the source is approaching the observer
f is the original frequency of the sound
By re-arranging the formula, we get
and by plugging the data of the problem into the equation, we find
so, the car is approaching the observer at 15.2 m/s.
This imply that the force applied by the gravity of the earth on the person, is equal to the force applied by the person on the earth.
According to the Newton's third law, for every force there is an equal reaction force, in the case of person standing on the earth, the gravity of the earth pulls the person by the same magnitude as the force applied by the person on the earth (which is equal to the weight of the person)..
