1. Turn off lights.
2. Unplug devices your not using.
3. Change filters on your heating system.
4. Dry laundry on a clothes line.
5. Take shorter showers.
6. Cover bare floors.
7. Put on a sweater to use your AC less.
8. Ride a bike and not drive a car.
9. Use smart power strips
10. Replace light bulbs
Answer:
water
Explanation:
the other options are elements while water is 2 elements
Answer:
- <u><em>Option C) Fr (francium)</em></u>
Explanation:
<em>Fluorine (F) </em>is not a metal; thus, the last option is discarded quickly.
The<em> most reactive metals</em> are the alkali metals, group 1 of the periodic table, because they have just one valence electron, which they can release more easily than other metals which have more valence electrons.
<em>Lithium(Li)</em> and <em>francium (Fr)</em> are alkali metals, while <em>aluminum (Al)</em> belongs to group 13, which means that it has 3 valence electrons.
Thus, aluminum is out of race too.
Lithium is in the second period (row 2 of the periodic table) while francium is in the last period (row 7).
The reactivity of metals in a group increases from top to bottom, because the valence electrons are shielded by many electrons (which are in the orbitals of less energy and closer to the nucleus of the atom), meaning that the valence eletrons can be released more easily.
Hence, the most reactive metal from the list is Fr (francium), option C).
The unknown of this problem is the experimental percent of water in the compound in order to remove the water of hydrogen, given the following:
Mass of crucible, cover and contents before heating 23.54 g
Mass of empty crucible and cover 18.82 g
Mass of crucible, cover, and contents after heating to constant mass 20.94 g
In order to get the answer, determine the following:
Mass of hydrated salt used = 23.54 g – 18.82 g = 4.72 g
Mass of dehydrated salt after heating = 20.94 g – 18.82 g = 2.12 g
Mass of water liberated from salt = 4.72 g – 2.12 g = 2.60 g
Then solve the percent of water in the hydrated salt by:
% water = (mass of water / mass of hydrated salt) x 100
% water = 2.60 g / 4.72 g x 100
% water = 55.08 % in the compound
This might get a little salt out but you will need to evaporate the water to completely get the salt out. Once you evaporate the water all that will be left is the salt