2.0 MOL is the correct answer I believe
Wavelength =speed/frequency
So speed/230
You need speed to get the answer
Answer:
1.35 moles of O²⁻
21.6 grams of O²⁻
Explanation:
We know that the charge on Aluminium ion is +3 (i.e. Al³⁺) while, the charge on Oxide ion is -2 (i.e. O²⁻). Therefore, the overall neutral Al₂O₃ compound has 2 Al³⁺ ions and 3 O²⁻ ions. Since, we can say that,
1 mole of Al₂O3 contains = 3 moles of O²⁻ ions
So,
0.450 moles of Al₂O₃ will have = X g of O²⁻
Solving for X,
X = 0.450 mol × 3 mol ÷ 1 mol
X = 1.35 moles of O²⁻
As the mass of an atom is mainly due to the presence of protons and neutrons hence, the addition of two electrons (-ve 2 shows two gained electron) to Oxygen will make a negligible change to the atomic masss of Oxygen because electron is said to be almost 1800 times lighter than proton. Hence, the ionic mass of O²⁻ will be 16 g/mol and the mass of given moles is calculated as,
Mass = Moles × Ionic Mass
Mass = 1.35 mol × 16 g/mol
Mass = 21.6 g
Answer:
47.5 mm are equal to 4.75 × 10⁻² m.
Explanation:
Meter and millimeter both are units of length. Millimeter is smaller unit while meter is larger unit. The one meter consist of thousand millimeter or we can say that one thousand millimeters are equal to one meter. In order to convert the meter value into millimeter we have to multiply the values with thousand.
we know that one meter is equal to 1000 millimeter.
1 m = 1000 mm
4.75 × 10⁻² × 1000 = 47.5 mm
47.5 mm are equal to 4.75 × 10⁻² m.
