Answer:

Explanation:
To convert atoms to moles, Avogadro's Number must be used: 6.022*10²³.
This tells us the amount of particles (atoms, molecules, etc.) in 1 mole of a substance. In this case it is the atoms of potassium. We can create a ratio.

Multiply by the given number of moles: 15.2

The moles of potassium cancel.

The denominator of 1 can be ignored.

Multiply.

The original measurement of moles has 3 significant figures, so our answer must have the same. For the number we calculated that is the hundredth place. The 3 in the thousandth place tells us to leave 5.

In 15.2 moles of potassium, there are <u>9.15*10²⁴ atoms of potassium.</u>
Answer:
Add G and H to determine the atomic mass for helium
Explanation:
Answer:
True
Explanation:
The arrhenius theory describes an acid as a substance that produces excess hydrogen ions when it interacts with water. Therefore, they increase the concentration of hydrogen ions in solutions.
An arrhenius base interacts with water to yield excess hydroxide ions in aqeous solutions.
Answer:
C boron, germanium, arsenic, silicon
Volume of H2 produced = 57.6576 L
<h3>Further explanation</h3>
Given
23.17 g Be
Required
Volume of H2
Solution
Reaction
Be(s)+H2O(g)→BeO(s)+H2(g)
mol Be :
= 23.17 g : 9 g/mol
= 2.574
From the equation, mol H2 : mol Be = 1 : 1, so mol H2 = 2.574
Volume H2(assumed at STP, 1 mol=22.4 L) :
= 2.574 x 22.4 L
= 57.6576 L