Answer:
D. They have the same number of protons as electrons.
Explanation:
Protons are found in the nucleus of the atom and have a positive charge while electrons orbit around the nucleus and have a negative charge. Usually, in a neutral atom of an element, the number of protons is equal to the number of electrons. This is why the atom has no charge because the positive and negative charges cancel out. When an atom loses an electron its charge turns positive while when it gains an electron its charge turns negative.
(missing in Q) : Calculate the concentration of CO & H2 & H2O when the system returns the equilibrium???
when the reaction equation is:
C(s) + H2O(g) ↔ H2(g) + CO(g)
∴ Kc = [H2] [CO] / [H2O]
and we have Kc = 0.0393 (given missing in the question)
when the O2 is added so, the reaction will be:
2H2(g) + O2(g) → 2H2O(g)
that means that 0.15 mol H2 gives 0.15 mol of H2O
∴ by using ICE table:
[H2O] [H2] [CO]
initial 0.57 + 0.15 0 0.15
change -X +X +X
Equ (0.72-X) X (0.15+X)
by substitution:
0.0393 = X (0.15+X) / (0.72-X) by solving for X
∴ X = 0.098
∴[H2] = X = 0.098 M
∴[CO] = 0.15 + X
= 0.15 + 0.098 = 0.248 M
∴[H2O] = 0.72 - X
= 0.72 - 0.098
= 0.622 M
This element is found in group 3A, period 3
<h3>Further explanation
</h3>
The maximum number of electrons that can be filled in the nth electron shell is 2n²(n=shell)
-
K shell (n = 1) maximum 2 x 1² = 2 electrons
- L shell (n = 2) maximum 2 x 2² = 8 electrons
- M shell (n = 3) maximum 2 x 3² = 18 electrons
- N shell (n = 4) maximum 2 x 4² = 32 electrons
Electron configuration of element X : 2.8.3 , so :
K shell = 2 ⇒1s²
L shell = 8⇒2s²2p⁶
M shell = 3⇒ 3s²3p¹
Block p: group 13-18 (has a 2p-6p configuration), also called a representative element because it includes metals, non-metals and metalloids
The outer shell 3s²3p¹ : located in group 3A and period 3
group⇒valence electron ⇒3
period⇒the greatest value of the quantum number n⇒3
Answer:
Einsteinium is heavier
Explanation:
Atomic weight is what we are referring to when figuring out how heavy an element is and is measured in amu (atomic mass units)
(This is also the same as the molar mass how heavy 6.022 x 10^23 atoms of a substance or element is which is measured in grams)
The atomic weight of an element can be found on a periodic table.
Europium has an atomic mass of approximately 152 amu (atomic mass units)
Einsteinium has an atomic mass of approximately 252 amu.
Einsteinium has a higher atomic weight so it's heavier.
There's another easier way of going about it where you don't even have to think about the actual number and basically just look at the element's atomic number and position on the periodic table.
Eu is 63
Es is 99
As the atomic number increases on the periodic table this means it's number of protons is greater.
Protons lie in the nucleus which has most of the atom's weight so the more protons the heavier it is.
Einsteinium has a higher atomic number meaning it has more protons so we can assume it's the heavier one.
Hope this helps!
Answer:
The electron from the ground state to occupy a next energy level. In this case,we say that the electron is excited
