Four significant figures would be B. Because 0's before the decimal are not important, but 0's after the decimal are.
Even though an atom may be smaller than another atom, it might have more mass. The mass of atoms, their size, and how they are arranged determine the density of a substance. Density equals the mass of the object divided by its volume; D = m/v. Objects with the same mass but different volume have different densities.
In one H₂O molecule, there are two hydrogen atoms along with one oxygen atom. So for every 1 oxygen atom (of which there are 2 of in an oxygen gas molecule) there needs to be 2 hydrogen atoms per oxygen( which in the equation of 2H2 +O2–> 2H2, that 2 H2 is broken down into 4 hydrogen atoms which means 2 hydrogen atoms have to bond to 1 oxygen atom and with 4 hydrogen atoms, there will be 2 atoms of oxygen which creates 2 molecules of water.
So to solve the question,
10.5g/2=5.25g of oxygen required to fully react with hydrogen to make water
Concept: According to the basic concept of the electronic configuration of the element, the electron can be filled first in those shell which has least energy or (n +l) value. Here, n is the principal quantum number on shell and l is the azimuthal quantum number.
Since, the first shell has least value of energy in any atom. So, it should be filled first.
Hence, the correct statement can be written as;
When diagramming an atom, the electron shells _nearest to _ the nucleus must be filled first.
The best answer is, “Two clear liquids combine and turn cloudy.”
When water freezes form a liquid to a solid. That’s a physical change.
When water boils, it forms bubbles. That’s a physical change.
When you mix ethanol and water, they form a clear solution. That’s a physical change.