The atomic number of an atom says how many protons it has. This number cant change, since the atomic number is what gives elements their identities (in the periodic table, at least).
The mass number, on the other hand, says how many protons AND neutrons the atom has (so, the sum of P+ and N0). So, electrons have nothing to do with this number.
Atoms are neutrally charged, which means there has to be an equal number of positive and negative particles. The negative particles of an atom are its electrons, and since our atom has 4 protons, it must also have 4 electrons.
Answer:
Option e. Blue/Violet
Explanation:
We know that when white light passes through a diffraction grating it spits into a band of seven colors or spectrum which includes the color in the order VIBGYOR that stands for Violet, Indigo, Blue, Green, Yellow, Orange and Red respectively.
Red light has the longest wavelength and is least scattered whereas Violet light with the shortest wavelength is the one to get most scattered and as we move far from bright spot at the center, there is an increase in the wavelength of light, thus the color that corresponds to the closest one is Violet with the shortest wavelength in the band.
Answer:
15m/s
Explanation:
add the two speeds and divide by 2
10+20=30
30/2=15
