Answer:

Explanation:
Hello,
In this case, since the Lewis theory is based on the bonds formation between atoms via the valence electrons, we can verify the chemical formula of the compound formed by strontium and nitrogen by noticing that strontium has two valence electrons as it is in group IIA, for that reason, two nitrogens should be available for bonding. Therefore, since nitrogen is in group VA, it is said that three electrons are required to attain the octet (maximum amount bonded electrons), for that reason, three strontiums are should be available for bonding. In such a way, the formula should be:

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Answer:
The answer to your question is 22.4 g of Ca(NO₃)₂
Explanation:
Data
mass of Ca(NO₃)₂ = ?
mass of water = 726 g
concentration = 0.2 m
Process
In Chemistry, there are two main units of concentration Molarity (M) and Molality (m). In this problem concentration is "m" then I will calculate molality.
1) Formula
molality = moles / mass of solvent
2.- Solve for moles
moles = molality x mass of solvent
-Substitution
moles = (0.2) x (0.726)
-Simplification
moles = 0.1452
3.- Convert moles to grams
Molar mass of Ca(NO₃)₂ = 40 + (14 x 2) + (6 x 16)
= 40 + 18 + 96
= 154 g
154 g of Ca(NO₃)₂ ---------------- 1 mol
x ---------------- 0.1452 moles
x = (0.1452 x 154) / 1
x = 22.4 g of Ca(NO₃)₂
I learned this in class! the answer is c
The myosin filaments remain in place as they pull the actin filaments inward!
Answer:
Subtract all the variables and do the opposite operation when added.
Explanation: