Answer:
Electromagnetic Wave Medium Matter:The ability to move or change an object, or what a wave
Longitudinal Wave Trough Rarefaction: The area in a longitudinal wave where the particles are close together.
Transverse Wave Energy Wavelength: The highest point of a transverse wave
Explanation:
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Complete Question:
To aid in the prevention of tooth decay, it is recommended that drinking water contain 0.800 ppm fluoride. How many grams of F− must be added to a cylindrical water reservoir having a diameter of 2.02 × 102 m and a depth of 87.32 m?
Answer:
2.23x10⁶ g
Explanation:
The concentration of the fluoride (F⁻) must be 0.800 ppm, which is 0.800 parts per million, so the water must have 0.800 g of F⁻/ 1000000 g of the solution. The density of the water at room temperature is 997 kg/m³ = 997x10³ g/m³. So, the concentration of the fluoride will be:
0.800 g of F⁻/ 1000000 g of the solution * 997x10³ g/m³
0.7976 g/m³
The volume of the reservoir is the volume of the cylinder: area of the base * depth. The base is a circumference, which has an area:
A = πR², where R is the radius = 1.01x10² m (half of the diameter)
A = π*(1.01x10²)²
A = 32047 m²
The volume is then:
V = 32047 * 87.32
V = 2.7983x10⁶ m³
The mass of the F⁻ is the concentration multiplied by the volume:
m = 0.7976 * 2.7983x10⁶
m = 2.23x10⁶ g
The molar mass of Na₂SO₄ -
2 x Na - 2 x23 = 46
1 x S - 1 x 32 = 32
4 x O - 4 x 16 = 64
total = 46 + 32 + 64 = 142 g/mol
the molarity of solution - 2.0 M
in 1 L of solution , 2.0 moles
Therefore in 2.5 L - 2 mol/L x 2.5 L = 5 mol
then the mass of Na₂SO₄ required = 142 g/mol x 5 mol = 710 g
i can think of 3 subatomic particles found in a nucleus protons, neutrons, and electrons
Explanation:
1
Number of nucleon =
Molarmassofnucleon
Massofatom
=
1.6726×10
−24
g/nucleon
3.32×10
−23
g
=19.8=20(approximately)
It is given that element comprises of 2 atoms
Hence,number of nucleon = 2×20=40
2
You have 4.70 mol H2O
There are two H atoms in 1 molecule H2O.
Therefore, there must be 2*4.70 = 9.40 mols H in 4.70 mols H2O.
How many mols O in 4.70 mols H2O? That's 4.70 mols, of course.
Said another way, you have 2 mols H for every 1 mol H2O and 1 mol O for every 1 mol H2O.
So for 50 mols H2O you have 100 mols H and 50 mol O.