Answer:
Lithium-7
Explanation:
By carefully inspecting the diagram we can see three different sub-particles.
1) Electrons (-vely charged, outside the nucleus)
2) Protons (+vely charged, Inside nucleus)
3) Neutrons (uncharged, Inside nucleus)
Mass Number:
Mass number is the number of protons and neutrons present in the nucleus of an atom.
Therefore, in our problem there are 4 neutrons and 3 protons.
So, the mass number is 7.
Atomic Number:
Atomic number is the number of protons present in the nucleus. This number shows the identity of an atom. If you go through the periodic table you will find that the atomic number 3 is for Lithium.
Result:
Lithium-7
Carbon have 4 valence electron
The electron configuration of C is : 1s2 2s2 2ps
the outer most s and p orbital contains 4 electrons and these are the valence electron of C atom
Key: to determine the valence electron of an element, you have to refer to the group it is located in, in the periodic table. (C is in group 4 (or 14) so VE = 4)
hope its clear enough
Answer:
We are given:
V(i) = 0.3 L V(f) = 0.36 L
P(i) = x pa P(f) = 400 pa
T(i) = T(f) = 293 k
Using the gas formula:
PV = nRT
Since n , R and T are constant,
PV = k (where k is a constant)
Hence we can say that:
P(i) * V(i) = P(f) * V(f)
x * 0.3 = 0.36 * 400
x = 14.4/0.3
x = 480 pascals
Hence the initial pressure is 480 pascals
Converting to Kpa, we have to divide by 1000
Initial pressure (Kpa) = 0.48
Lol it literally says that he covered the distance in three seconds so I believe it would be three