Ethanol is polar because the oxygen atoms attract electrons because of their higher electronegativity than other atoms in the molecule. Thus the -OH group in ethanol has a slight negative charge. Ammonia (NH3) is polar. Sulfur dioxide (SO2) is polar.
The reactivity of metals increases as you move left in a period and as you move down in a group, so Marie needs to know the period and group of the element inside each box. Boxes that show locations in groups 1 or 2 or in period 8 contain the most reactive elements.
Answer:
1.2 x 10⁵ moles Ag (2 sig. figs.)
Explanation:
1 mole any substance (elements or compounds) => 6.023 x 10²³ particles of specified substance
∴ 6.9 x 10²⁸ atoms Ag = 6.9 x 10²⁸ Ag atoms / 6.023 x 10²³ Ag atoms/mole Ag
= 1.145608501 x 10⁵ moles Ag (calculator answer)
= 1.2 x 10⁵ moles Ag (2 sig. figs.)
