Question

15 multiple choice 1 point
what is avogadro’s number?
○ 6.022*10¹¹
○ 23.022*10⁶⁰
○ 6.022*10
○ 6.022*10²³
clear my selection
16 multiple choice 1 point
how many grams are in one mole of copper?
○ 12.0g
○ 63.5g
○ 118.7g
○ 24.3g
clear my selection

Explanation:

Question 15 (What is Avogadro’s number?)

Avogadro's number is a fundamental constant in chemistry (a subfield of Natural Science) representing the number of particles (atoms, molecules, ions, etc.) in one mole of a substance. By definition, Avogadro's number is approximately \( 6.022\times10^{23} \). The other options have incorrect exponents or coefficients.

The molar mass of an element is numerically equal to its atomic mass (in atomic mass units) and is expressed in grams per mole. The atomic mass of copper (Cu) is approximately 63.5 atomic mass units, so one mole of copper has a mass of approximately 63.5 grams. The other options correspond to the molar masses of different elements (e.g., 12.0 g is for carbon, 24.3 g is for magnesium, 118.7 g is for tin).

Answer:

D. \( 6.022^{*}10^{23} \)

Question 16 (How many grams are in one mole of copper?)