I’m not sure what the answer is but I hope someone can help you
Answer:
true
Explanation:
Because Mercury can be solidified when its temparature us brought to its freezing point. However, when returned to room temparature conditions, mercury does not exist in solid state for long, and returns back to its more common liquid form.
Answer:
A- beryllium
B- calcium
C- magnesium
Explanation
NOTE: all element in group 2 have 2 balance electrons
First let’s start with B- number of electrons= number of protons which is equal to the atomic number. therefore, the answer is calcium as it’s atomic number is 20
C- magnesium will have three energy levels considering it has 12 electrons (2,8,2).
A- beryllium is the lightest one in group 2 as it has the atomic mass of 9.0122.
Answer:
53j/k
Explanation:
ΔH = TΔS => ΔS = ΔH/T = 1.5 x 10⁴ joules/283 Kelvin = 53 joules/K
Answer:
0.10M of Ba²⁺ is the concentration of the metal in excess
Explanation:
Based on the chemical reaction:
K₂CO₃(aq) + Ba(NO₃)₂(aq) → BaCO₃(s) + 2KNO₃(aq)
<em>1 mole of potassium carbonate reacts per mole of barium nitrate</em>
<em />
To solve this question we need to find the moles of each salt to find then the moles of Barium in excess:
<em>Moles K₂CO₃:</em>
0.025L * (0.25mol / L) = 0.00625moles K₂CO₃ = moles CO₃²⁻
<em>Moles Ba(NO₃)₂:</em>
0.030L * (0.40mol/L) = 0.012 moles of Ba(NO₃)₂ = 0.012 moles of Ba²⁺
That means moles of Ba²⁺ that don't react are:
0.012 mol - 0.00625mol = 0.00575 moles Ba²⁺
In 25 + 30mL = 55mL:
0.00575 moles Ba²⁺ / 0.055L =
<h3>0.10M of Ba²⁺ is the concentration of the metal in excess</h3>
which is called the Avogadro’s number.