Answer:
Manganese: Mn
Explanation:
The elestron configuration would show this is 25 electrons
Atomic number : 25
this electron configuration ends in 
half of the d subshell which is 10
The correct answer is option 1. Carbon dioxide is nonpolar because the shape of the molecule is symmetrical. It is a linear molecule where the oxygen atoms are symmetrical on each end. CO2 molecule do not have a region of unequal sharing.
If you’re talking about noble gases, the answer would be A. Since noble gases already have 8 electrons, they don’t tend to form chemical bonds. And elements need just 8 electrons on there shells to be stable.
a) The reaction is exothermic since the overall enthalpy change is negative. this means that the system has lost energy to the environment, namely, the apparatus and due to drought.
b) We first calculate the number of moles in 3.55 grams of magnesium.
number of moles= mass/ atomic mass
=3.55/24
=0.1479 moles(to 4sf)
now, if 2 moles of magnesium give -1204kJ
How much energy is given by 0.1479 moles
= (0.1479×-1204kJ)
=-89.0358kJ (don't forget the negative sign)
c) two molesof MgO produces -1204kJ of energy
then -234kJ will be produced by
=(-234kJ×2moles)/1204kJ
=0.3887moles
one mole of MgO weighs 24+16=40
therefore the mass produced is 0.3887moles×40=15.548grams
(d) we first find the number of moles of MgO in 40.3 grams
number of moles=mass/RFM
=40.3g/40= 1.0075moles
if 2 moles of MgO give 1204 kJ then decomposing 1.0075 moles requires
(1.0075 moles×1204kJ)/2=606.515kJ
<span>evaporation is the process that describe changing of water from liquid to gas</span>
