An element with 8 valence electrons is Neon (Ne).
Ps: Any element under group 18 has 8 valence electrons except for Helium (He).
The number of grams of NaOH that are needed to make 500 ml of 2.5 M NaOH solution
calculate the number of moles =molarity x volume/1000
= 2.5 x 500/1000 = 1.25 moles
mass = moles x molar mass of NaOH
= 1.25 x40= 50 grams of NaOH
The combustion of Methane produces CO₂ and water;
CH₄ + 2 O₂ → CO₂ + 2 H₂O
According to balance equation,
1 Mole of CH₄ on combustion give = 2 Moles of H₂O
So,
2 Moles of CH₄ will produce = X Moles of H₂O
Solving for X,
X = (2 Moles × 2 Moles) ÷ 1 Mole
X = 4 Moles
Result:
4 Moles of H₂O is produced on combustion of 2 Moles of CH₄.
Answer:
the 3rd option for make sense,so that's out
Dalton was the pioneer behind the atomic model,but he certainly didn't believe in the nucleus or electrons,much lest electron shells.
Chadwick's discovery was the discovery of the neutron,not electron energy levels.
Niels Bohr's model was an attempt at explaining the hydrogen atom's spectrogram,followed by Erwin Schrödinger.Thus the first option is the answer
Answer:
10573.9K
Explanation:
Using pressure law equation;
P1/T1 = P2/T2
Where;
P1 = initial pressure (mmHg)
P2 = final pressure (mmHg)
T1 = initial temperature (K)
T2 = final temperature (K)
According to the information provided in this question,
P1 = 46mmHg
P2 = 760mmHg
T1 = 640K
T2 = ?
Using P1/T1 = P2/T2
46/640 = 760/T2
Cross multiply
640 × 760 = 46 × T2
486400 = 46T2
T2 = 486400 ÷ 46
T2 = 10573.9K