Answer:
Answer 9: Oxygen is atomic number 8 on the periodic table, which means it has 8 protons!
Explanation:
Oxygen's 8 electrons are negatively charged, and they orbit the atomic nucleus and balance the positive charge of the 8 protons. The positive charge of 1 proton exactly cancels the negative charge of 1 electron.
Answer 1.) Eu3+ ( Europium with charge of + 3 ) Answer 2.) Sn-188 with a -2 charge So, we know that 50 protons = the atomic mass= Sn (tin) Now, we have to find the atomic mass/ atomic mass= protons+neutrons/ plugin= 50 protons+ 68 neutrons= 118 amu (atomi mass unit) Then , we have 48 eletrons ( e-) - ( 50 protons ( positive chage ))= -2 charge! Final plugin: Sn-188 with a -2 charge.
Answer:
Approximately .
Explanation:
Make use of the molar mass data () to calculate the number of moles of molecules in that of :
.
Make sure that the equation for this reaction is balanced.
Coefficient of in this equation: .
Coefficient of in this equation: .
In other words, for every two moles of that this reaction consumes, two moles of would be produced.
Equivalently, for every mole of that this reaction consumes, one mole of would be produced.
Hence the ratio: .
Apply this ratio to find the number of moles of that this reaction would have produced:
.
Answer:
A) positive; added
Explanation:
Based on the reaction:
2NaHCO3(s) + 129kJ → Na2CO3(s) + H2(g) + CO2(g)
<em>2 moles of NaHCO3 requires 129kJ to produce 1 mole of Na2CO3, 1 mole of H2 and 1 mole of CO2.</em>
<em />
That means, the energy must be added being, thus, an exothermic reaction. The exothermic reactions have ΔH >0.
Thus, right answer is:
A) positive; added