Well, knowing that group 2A elements are metals, and metals lose electrons to gain a full electron shell, we can eliminate B and D. Knowing that these are 2 electrons, that the group 2A element provides to another atom, to form an ion.
The solution is C. Lose 2 electrons.
Answer:
f = 0.084 s⁻¹
Explanation:
Given data:
Frequency of light = ?
Wavelength = 35.6 m
Solution:
Formula:
Speed of light = wavelength × frequency
Speed of light = 3× 10⁸ m/s
by putting values,
3× 10⁸ m/s = 35.6 m × f
f = 3× 10⁸ m/s / 35.6 m
f = 0.084 s⁻¹
First write the balanced equation of this reaction:
2H2 + O2 —> 2H2O
mol of H2= 0.60 gH2/2.02 gH2 = 0.297 mol
There are 2 mol of H2 for every 2 mol of H2O so the number of mol of H2 is equal to the number of mol of H2O.
g of H2O = 0.297 mol H2O • 18.02 gH2O = 5.35 g H2O
Do the same thing for O2:
mol of O2 = 4.8 gO2/32.0 gO2 = 0.15 mol of O2
There is 1 mol of O2 for every 2 mol of H2O so multiply 0.15 • 2 to get the number of mol of H2O
g of H2O = 0.30 mol H2O • 18.02 gH2O = 5.41 g H2O
The correct answer is 5.35 g H2O (or 5.4 g if checking significant figures) because O2, in this case, is the limiting reactant of this reaction.
Because science have measurements.
