Answer:
The answer is D) all of the above
Explanation:
This is because if something has mass then it is composed of matter.
Can I have brainliest please?
Answer:
the stronger light 5.5 m apart from the total illumination
Explanation:
From the problem's statement , the following equation can be deducted:
I= k/r²
where I = intensity of illumination , r= distance between the point and the light source , k = constant of proportionality
denoting 1 as the stronger light and 2 as the weaker light
I₁= k/r₁²
I₂= k/r₂²
dividing both equations
I₂/I₁ = r₁²/r₂²=(r₁/r₂)²
solving for r₁
r₁ = r₂ * √(I₂/I₁)
since we are on the line between the two light sources , the distance from the light source to the weaker light is he distance from the light source to the stronger light + distance between the lights . Thus
r₂ = r₁ + d
then
r₁ = (r₁ + d)* √(I₂/I₁)
r₁ = r₁*√(I₂/I₁) + d*√(I₂/I₁)
r₁*(1-√(I₂/I₁)) = d*√(I₂/I₁)
r₁ = d*√(I₂/I₁)/(1-√(I₂/I₁)) =
r₁ = d/[√(I₁/I₂)-1)]
since the stronger light is 9 times more intense than the weaker
I₁= 9*I₂ → I₁/I₂ = 9 →√(I₁/I₂)= 3
then since d=11 m
r₁ = d/[√(I₁/I₂)-1)] = 11 m / (3-1) = 5.5 m
r₁ = 5.5 m
therefore the stronger light 5.5 m apart from the total illumination
<u>Answer:</u> The concentration of
ions are 2.797 ppm and 0.212 ppm respectively.
<u>Explanation:</u>
To calculate the mass of solution, we use the equation:

Volume of gold = 100 L = 100000 mL (Conversion factor: 1 L = 1000 mL)
Density of gold = 1.001 g/mL
Putting values in above equation, we get:

To calculate the concentration in ppm (by mass), we use the equation:

- <u>Calculating the concentration of calcium ions:</u>
Mass of
ions = 0.280 g
Putting values in above equation, we get:

- <u>Calculating the concentration of magnesium ions:</u>
Mass of
ions = 0.0220 g
Putting values in above equation, we get:

Hence, the concentration of
ions are 2.797 ppm and 0.212 ppm respectively.
One mole represents 6.022∙1023 separate entities, just like one dozen represents 12 objects. So, if there are 6.022∙1023 H2O molecules, that is the same as one mole of water.
Answer is: Ksp for strontium arsenate is 2.69·10⁻¹⁸.
Balanced chemical reaction (dissociation):
Sr₃(AsO₄)₂(s) → 3Sr²⁺(aq) + AsO₄³⁻(aq).
s(Sr₃(AsO₄)₂) = 0.0650 g/L.
s(Sr₃(AsO₄)₂) = 0.0650 g/L ÷ 540.7 g/mol = 1.2·10⁻⁴ mol/L.
s(Sr²⁺) = 3s(Sr₃(AsO₄)₂).
s(AsO₄³⁻) = 2s(Sr₃(AsO₄)₂).
Ksp = s(Sr²⁺)³ · s(AsO₄³⁻)².
Ksp = (3s)³ · (2s)².
Ksp = 108s⁵.
Ksp = 108 · (1.2·10⁻⁴ mol/L)⁵ = 2.69·10⁻¹⁸.