Answer:
50 g of K₂CO₃ are needed
Explanation:
How many grams of K₂CO₃ are needed to make 500 g of a 10% m/m solution?
We analyse data:
500 g is the mass of the solution we want
10% m/m is a sort of concentration, in this case means that 10 g of solute (K₂CO₃) are contained in 100 g of solution
Therefore we can solve this, by a rule of three:
In 100 g of solution we have 10 g of K₂CO₃
In 500 g of solution we may have, (500 . 10) / 100 = 50 g of K₂CO₃
The answer is A
trust me i know
when I was really confused in science class and I think a lot but not found in book then I get help from my friend but he also don't know that and then finally my teacher solves it the question was what makes a rainbow .
The Bohr model used to be used but it signifies that electrons stay stationary. The current model uses electron clouds in order to predict the location of an electron within an atom.
Additionally, we can predict the location of an electron, but we cannot exactly pinpoint it. So, the current atomic model cannot have a clear and exact placement for every electron around the nucleus of an atom. It also cannot have a clear and distinct border surrounding the nucleus of an atom where electrons are located.
Therefore, the current atomic model has a predicted area surrounding the nucleus where the electron could be located.