Answer:
electron: orbiting around the nucleus
proton: inside the nucleus
neutron: inside the nucleus
First we need to find the number of moles that 43.9g of gallium metal is. We can do this by finding the molar weight of gallium and cross-multiplying to cancel out units:
So we are dealing with 0.63 moles of gallium metal.
We can take from the balanced equation that 4 moles of gallium metal will react completely with 3 moles of oxygen gas. We can take this ratio and make a proportion to find the amount of oxygen gas, in moles, that will react completely with 0.63 moles of gallium metal:
Cross multiply and solve for x:
So now we know that 0.47 moles of oxygen gas will react with 43.9g of gallium metal.
Answer:
4.427 × 10⁵
Explanation:
In mathematics, rounding up a number is a way to get a more simpler figure but not too distant from the original number. Rounding up a whole number like this (442722) to significant figures means having only four non-zero digits in the figure i.e. 442722 ~ 442700.
This means that 442722 has been rounded up to 4s.f. Hence, to use scientific notations to represent our answer, we count the number of decimal places from right to left i.e.
442700 = 5 decimal places if the point is between 4 and 4 i.e. 4.427
Therefore, the figure 442700 can be written as 4.427 × 10⁵ using scientific notation.