The atomic number is the simply the number of protons in the atom. So in the first row with atomic number 2, the number of protons is 2.
If the atom has no charge, which I think you can assume for all of these, the number of electrons is equal to the number of protons. So the number of electrons is also 2.
The number of neutrons (which are the particles with no charge in the nucleus) is simply the mass number minus the atomic number i.e. 4 - 2 = 2.
The isotopic symbol is the symbol which is found on the periodic table of elements. There are 2 numbers associated which each element on the table. The larger is the mass number and the smaller is the atomic number. The atomic number or number of protons is what identifies the element. Looking at the periodic table ( https://sciencenotes.org/wp-content/uploads/2015/01/PeriodicTableOfTheElementsBW.pdf or https://simple.wikipedia.org/wiki/Periodic_table_(big) ), it can be seen that the element on the first row above with an atomic number of 2 is Helium with a symbol He. The number that is included with the name is simply the mass number which is 4 in this case, which tells us that this type of helium has 2 neutrons.
Another type (or isotope) of helium is Helium-3 which has one neutron.
Try the next row and post back if you have trouble with it
The law of superposition helps scientists determine the relative age of a layer of sedimentary rock. the law of superposition is <span>a basic </span>law<span> of geochronology, stating that in any undisturbed sequence of rocks deposited in layers, the youngest layer is on top and the oldest on bottom, each layer being younger than the one beneath it and older than the one above it</span> .
hope this helps :)
Answer:
When equal and opposite forces meet each other, it results in motion and they would repel away from each other, causing the asteroid to be sent away from the earth.
Explanation:
Newton's Third Law states that every action has an equal and opposite reaction.
Answer:
The new intensity decreases by a factor of 16.
Explanation:
The intensity of sound wave is given by :
P is power
A is area
or
, r is distance from the source
If the distance from the source is increased by a factor of 4, r' = 4r
So,
So, the new intensity decreases by a factor of 16.
The used work of energy output is 496*2.1=1041.6 J. And the actual work of energy output is 1127*0.85=957.95 J. The percentage efficiency is 957.95/1041.6*100%=91.97 %.
