Answer:
A- beryllium
B- calcium
C- magnesium
Explanation
NOTE: all element in group 2 have 2 balance electrons
First let’s start with B- number of electrons= number of protons which is equal to the atomic number. therefore, the answer is calcium as it’s atomic number is 20
C- magnesium will have three energy levels considering it has 12 electrons (2,8,2).
A- beryllium is the lightest one in group 2 as it has the atomic mass of 9.0122.
Remember the formula as per the second Law of Newton: F = m*a
And also remember that the weight is the force with which the mass is attracted by the planet (or satellite in the case of the moon).
With that information you can answer the questions:
a) Weight = F = m*a
m = 175 slugs = 175 lbm
i) Earth
a = 32.17 ft/s^2
Weight on Earth = 175 lbm * 32.17 ft / s^2 = 5,629.75 poundal
ii) Moon
a = [1/6] 32.17 ft/s^2
Weight on the Moon = [1/6]*5,629.75 poundal = 938.29 poundal
b) Force = 355 poundal
m = 25.0 slug
a in m/s^2 = ?
First calculate the force in ft/s^2
F = m*a => a = F/m = 355 poundal / 25.0 slug = 14.2 ft/s^2
Conversion:
14.2 ft / s^2 * [ 0.3048 m/ft] = 4.32816 m/s^2
Answer: 4.33 m/s^2
It doesn't because pepper does not dissolve
This problem is providing us with the percent composition of a compound containing magnesium, nitrogen, oxygen and water. Thus, the empirical formula is required and found to be Mg(NO₃)₂·6H₂O.
<h3>Empirical formulas</h3>
In chemistry, empirical formulas are used in order to figure out the minimum whole-number representation of a molecular formula, which contains the actual number of atoms.
Thus, we start determining it by assuming the given percentages as masses and calculating the moles with the atomic or molar mass of the involved species:
![n_{Mg}=\frac{9.37}{24.3} =0.386\\\\n_{N}=\frac{10.3}{14.01}=0.735\\ \\n_O=\frac{37.52}{16.00}=2.32\\ \\n_{H_2O}=\frac{42.18}{18.02}=2.34](https://tex.z-dn.net/?f=n_%7BMg%7D%3D%5Cfrac%7B9.37%7D%7B24.3%7D%20%3D0.386%5C%5C%5C%5Cn_%7BN%7D%3D%5Cfrac%7B10.3%7D%7B14.01%7D%3D0.735%5C%5C%20%5C%5Cn_O%3D%5Cfrac%7B37.52%7D%7B16.00%7D%3D2.32%5C%5C%20%5C%5Cn_%7BH_2O%7D%3D%5Cfrac%7B42.18%7D%7B18.02%7D%3D2.34)
Next, we divide by the 0.386 as the smallest number of moles in order to determine their subscripts in the chemical formula:
![Mg}=\frac{0.386}{0.386} =1\\\\n_{N}=\frac{0.735}{0.386}=2\\\\n_O=\frac{2.32}{0.386}=6\\\\n_{H_2O}=\frac{2.34}{0.386}=6](https://tex.z-dn.net/?f=Mg%7D%3D%5Cfrac%7B0.386%7D%7B0.386%7D%20%3D1%5C%5C%5C%5Cn_%7BN%7D%3D%5Cfrac%7B0.735%7D%7B0.386%7D%3D2%5C%5C%5C%5Cn_O%3D%5Cfrac%7B2.32%7D%7B0.386%7D%3D6%5C%5C%5C%5Cn_%7BH_2O%7D%3D%5Cfrac%7B2.34%7D%7B0.386%7D%3D6)
Hence, the empirical formula turns out to be Mg(NO₃)₂·6H₂O, which is actually a hydrate (hexahydrate).
Learn more about percent composition: brainly.com/question/12247957