Answer:
The naswer to your question is Scandium
Explanation:
43 means the atomic mass is normally presented as a power
21 means atomic number is always a subscript
₂₁ ? ⁴³
Technetium ₄₃Tc⁹⁸
Scandium ₂₁Sc⁴⁴
Titanium ₂₁Ti⁴⁷
Cobalt ₂₇Co⁵⁹
The balanced chemical reaction for this would be written as:
2Mg + O2 = 2MgO
We use this reaction and the amount of the reactant given to calculate for the amount of magnesium oxide that is produced. We do as follows:
1.5 g Mg (1 mol / 24.31 g) ( 2 mol MgO / 2 mol Mg ) (40.30 g /1 mol ) = 2.49 g MgO produced
Answer:
2.1 kg of water
Explanation:
Step 1: Given data
- Moles of lithium bromide (solute): 4.3 moles
- Molality of the solution (m): 2.05 m (2.05 mol/kg)
- Mass of water (solvent): ?
Step 2: Calculate the mass of water required
Molality is equal to the moles of solute divided by the kilograms of solvent.
m = moles of solute/kilograms of solvent
kilograms of solvent = moles of solute/m
kilograms of solvent = 4.3 mol /(2.05 mol/kg) = 2.1 kg
Explanation:
According to the law of conservation of mass, it makes a generalized observation that there will occur no change in the mass of a substance even if it undergoes a chemical reaction.
Whereas this law of conservation does not explain any phenomenon of why this conservation of mass occurs.
Therefore, the given statements are classified as follows.
A) It was developed from past observations - Ture
B) It is subject to experimentation and revision - True
C) It explains why mass is conserved - False
D) It predicts future observations - True
