Answer:
31
Explanation:
In order for an atom to have a neutral charge, it needs to have the same number of protons and electrons. You can see by the illustration that the atomic number is 31, so this element has 31 protons. Knowing that, we also know that it must have 31 electrons to be neutral.
The answer would be E, it shows students how the different environments appear, since you can visually see it.
Answer:
34 g/100 mL
Explanation:
The solubility of a compound can be expressed in g/100mL, for this we must divide the mass of the compound that dissolves in the solute by the volume of the solvent.
The solvent, in this case, is water, and that mass of the solute X that dissolved is the mass that was recovered after the solvent was drained and evaporated. So the solubility of X (S) is:
S = 0.17 kg/5L
S = 170g/5000mL
S = 170g/(5*1000)mL
S = 34 g/100 mL
I just took that quiz , it’s A
Answer:
The mass of water is 36 g.
Explanation:
Mass of hydrogen = 4 g
Mass of water = ?
Solution:
First of all we will write the balance chemical equation:
2H₂ + O₂ → 2H₂O
Number of moles of hydrogen = mass / molar mass
Number of moles of hydrogen = 4 g/ 2 g/mol
Number of moles of hydrogen = 2 mol
Now we compare the moles of water with hydrogen from balance chemical equation.
H₂ : H₂O
2 : 2
Mass of water = moles × molar mass
Mass of water = 2 mol × 18 g/mol
Mass of water = 36 g
If the water oxygen is in excess than mass of water would be 36 g.
