The correct answer to your question is noble gases are stable <span>due to having the maximum number of valence electrons their outer shell can hold. Meaning their outer shells are stable.
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A million years old
Duhhhh
Answer:
C.) 35
Explanation:
The mass is made up of the total protons and neutrons in an atom. Protons and neutrons both have a mass of 1 amu. Electrons are not included in this measurement because they have an insignificant mass (practically 0).
(17 protons x 1 amu) + (18 neutrons x 1 amu) = 35 amu
Therefore, if an atom contains 17 protons and 18 neutrons, the mass should be 35 amu.
Answer: 162.8 grams
Explanation:
Magnesium nitrate has a chemical formula of Mg(NO3)2.
Given that:
Number of moles of Mg(NO3)2 = 1.1 moles
Mass in grams of Mg(NO3)2 = ?
For Molar mass of Mg(NO3)2, use atomic mass of magnesium = 24g, nitrogen = 14g, oxygen = 16g
Mg(NO3)2 = 24g + (14g + 16gx3) x 2
= 24g + (14g + 48g) x 2
= 24g + (62g) x 2
= 24g + 124g
= 148g/mol
Now, apply the formula:
Number of moles = Mass in grams / molar mass
1.1 moles = Mass / 148g/mol
Mass = 1.1 moles x 148g/mol
Mass = 162.8 grams
Thus, there are 162.8 grams of magnesium nitrate.
Answer:
0.121 moles of aluminum metal are required to produce 4.04 L of hydrogen gas at 1.11 atm and 27 °C by reaction with HCl
Explanation:
This is the reaction:
2 Al(s) + 6 HCl(aq) → 2 AlCl₃ (aq) + 3 H₂(g)
To make 3 moles of H₂, we need 2 moles of Al.
By conditions given, we will find out how many moles of H₂ do we have.
Let's use the Ideal Gas Law
P. V = n . R . T
1.11 atm . 4.04L = n . 0.082 L.atm/mol.K . 300K
(1.11 atm . 4.04L) / (0.082 mol.K/L.atm . 300K) = n
0.182 mol = n
So the rule of three will be:
If 3 moles of H₂ came from 2 moles of Al
0.182 moles of H₂ will come from x
(0.182 .2) / 3 = 0.121 moles