To determine the mass of the sample, first find the volume difference after and before the aluminum was placed, the volume change is equal to the volume of the submerged object, in this case aluminum.
Then knowing volume of aluminum and the density of it, we can solve for the mass.
D = m/v
Dv = m
2.7 g/ml • 8 ml = 21.6 grams.
Elements are substances that contain only 1 kind of atom.
9 grams of hydrogen gas (H2) will SC Johnson need to react in order to make 1 bottle of Windex.
Explanation:
Balance equation for the formation of ammonia from H2 gas.
N2 + 3H2 ⇒ 2 ![NH_{3}](https://tex.z-dn.net/?f=NH_%7B3%7D)
Given
mass of ammonia in 1 bottle of windex = 51 gram
atomic mass of ammonia 17.01 gram/mole
number of moles = ![\frac{mass}{atomic mass of 1 mole}](https://tex.z-dn.net/?f=%5Cfrac%7Bmass%7D%7Batomic%20mass%20of%201%20mole%7D)
number of moles = ![\frac{51}{17.01}](https://tex.z-dn.net/?f=%5Cfrac%7B51%7D%7B17.01%7D)
= 3 moles of ammonia is formed.
in 1 bottle of windex there are 3 moles of ammonia 0r 51 grams of ammonia.
From the equation it can be found that:
3 moles of hydrogen reacted to form 2 moles of ammonia
so, x moles of hydrogen will react to form 3 moles of ammonia.
= ![\frac{3}{x}](https://tex.z-dn.net/?f=%5Cfrac%7B3%7D%7Bx%7D)
x = 4.5 moles of hydrogen will be required.
to convert moles into gram formula used:
mass = atomic mass x number of moles (atomic mass of H2 is 2grams/mole)
= 2 x 4.5
= 9 grams of hydrogen.
I think the answer might be B but i’m not positive
Answer:
1) The elements have filled valence levels.
Explanation:
Since they have filled valence levels, they're stable and don't need to electrons to fill their valence shells since they're already full.
2) False, They do have electrons
3) False, He does have only one electron shell, but going down the periods, every next element have one more electron shell than a preceding one has.
4)False, they're actually the smallest atoms of their respective period