D. Matter and energy are the same.
Moles of NaN3 at STP = volume of gas / 22.4 = 11.5/22.4 = 0.5mole. Massof NaN3 = moles of NaN3 x molecular weight = 0.5 x 65 = 32.5 grams.
Data:
Molar Mass of NaOH = 40 g/mol
Solving: <span>According to the Law Avogradro, we have in 1 mole of a substance, 6.02x10²³ atoms/mol or molecules
</span>
1 mol -------------------- 6.02*10²³ molecules
y mol -------------------- 2.70*10²² molecules
6.02*10²³y = 0.270*10²³


Solving: <span>Find the mass value now
</span>
40 g ----------------- 1 mol of NaOH
x g ------------- 0.04 mol of NaOH


Answer:
The mass is 1.6 grams
A neutral atom of potassium has 19 electrons.
<span>V equals one-third times pi times r squared times h</span>