Answer:
The answer to your question is 203.8 g
Explanation:
Data
Average atomic mass = ?
Centium-200
Centium-203
Centium-209
Equal amounts
Process
1.- Determine the abundance of each isotope.
If they are in equal amounts in nature, just divide 100 by 3
100/3 = 33.33 % or 0.333
2.- Determine the Average atomic mass
Average atomic mass = Atomic mass 1 x abundance + Atomic mass 2 x
abundance + Atomic mass 3 x abundance
- Substitution
Average atomic mass = 200 x 0.333 + 203 x 0.333 + 209 x 0.333
- Simplification
Average atomic mass = 66.6 + 67.6 + 69.6
Result
Average atomic mass = 203.8 g
Answer:
2.4 g
Explanation:
Step 1: Given data
- Initial pressure (P₁): 755 torr
- Final pressure (P₂): 1.87 atm
Step 2: Convert "P₁" to atm
We will use the conversion factor 1 atm = 760 torr.
755 torr × 1 atm/760 torr = 0.993 atm
Step 3: Convert "T" to K
We will use the following expression.
K = °C + 273.15
K = 25°C + 273.15 = 298 K
Step 4: Calculate the initial number of moles of He
We will use the ideal gas equation.
P₁ × V = n₁ × R × T
n₁ = P₁ × V/R × T
n₁ = 0.993 atm × 16.8 L/(0.0821 atm.L/mol.K) × 298 K
n₁ = 0.682 mol
Step 5: Calculate the final number of moles of He
We will use the ideal gas equation.
P₂ × V = n₂ × R × T
n₂ = P₂ × V/R × T
n₂ = 1.87 atm × 16.8 L/(0.0821 atm.L/mol.K) × 298 K
n₂ = 1.28 mol
Step 6: Calculate the moles of He added
n = n₂ - n₁
n = 1.28 mol - 0.682 mol
n = 0.60 mol
Step 7: Convert "n" to mass
The molar mass of He is 4.00 g/mol
0.60 mol × 4.00 g/mol = 2.4 g
Your answer is B ;) the movement of electrons cause electrical energy :)
Answer:
a. ionic, 211.62g/mol
b. molecular, 149g/mol
c. molecular, 342g/mol
Explanation:
Ionic Compound: These are compounds (2 or more elements) where atoms of the element have lost or gained electrons, thus they are ions, thus the name ionic. An easy way to identify ionic compounds is to see if there are any metals. Metals tend to give up their electron to a non-metal. It maybe helpful to familiarize which parts of the periodic table have metals and non-metals.
Molecular Compounds: These are compounds (2 or more elements) that are neutral. An easy way to identify them is that the compound is made up of just non-metals.
Molar Mass is the masses of each individual element in the compound. Refer to the periodic table for the masses and add them up carefully, remember to multiply their mass based on how many molecules there are in the compound, like for a, we can find the mass of NO3, but we need to multiply it by 2 since we have 2 molecules of NO3.
a. Sr(NO3)2
Sr= 87.62
NO3= 14 + (3 x 16)= 62
Sr + 2 (NO3)
87.62 + (2 x 62)= 211.6
b. (NH4)3PO4
NH4= 14 + 4 = 18
PO4= 30.97 + (4 x 16)= 94.9
(NH4 x 3) + PO4
(18 x 3) + 94.9 = 149
c. C12H22O11
(12 x C) + (22 x H) + (11 x O)
(12 x 12) + (22 x 1) + (11 x 16)
144 + 22 + 176= 342
