Answer:

Explanation:
Density is found by dividing the mass by the volume.

The mass of the object is 11 grams and the volume is 13 milliliters.

Substitute the values into the formula.

Divide.

Round to the nearest hundredth. The 6 in the thousandth place tells us to round the 4 to a 5.

The density is about <u>0.85 grams per milliliter.</u>
Answer is: silicon isotope with mass number 28 has highest relative abundance, this isotope is the most common of these three isotopes.
Ar₁(Si) = 28; the average atomic mass of isotope ²⁸Si.
Ar₂(Si) =29; the average atomic mass of isotope ²⁹Si.
Ar₃(Si) =30; the average atomic mass of isotope ³⁰Si.
Silicon (Si) is composed of three stable isotopes, ₂₈Si (92.23%), ₂₉Si (4.67%) and ₃₀Si (3.10%).
ω₁(Si) = 92.23%; mass percentage of isotope ²⁸Si.
ω₂(Si) = 4.67%; mass percentage of isotope ²⁹Si.
ω₃(Si) = 3.10%; mass percentage of isotope ³⁰Si.
Ar(Si) = 28.086 amu; average atomic mass of silicon.
Ar(Si) = Ar₁(Si) · ω₁(B) + Ar₂(Si) · ω₂(Si) + Ar₃(Si) · ω₃(Si).
28,086 = 28 · 0.9223 + 29 · 0.0467 + 30 · 0.031.
Answer:
Cp = 0.237 J.g⁻¹.°C⁻¹
Explanation:
Amount of energy required by known amount of a substance to raise its temperature by one degree is called specific heat capacity.
The equation used for this problem is as follow,
Q = m Cp ΔT ----- (1)
Where;
Q = Heat = 640 J
m = mass = 125 g
Cp = Specific Heat Capacity = <u>??</u>
ΔT = Change in Temperature = 43.6 °C - 22 °C = 21.6 °C
Solving eq. 1 for Cp,
Cp = Q / m ΔT
Putting values,
Cp = 640 J / (125 g × 21.6 °C)
Cp = 0.237 J.g⁻¹.°C⁻¹
<span>moles glucose = 19 g / 180 g/mol= 0.105
M = 0.105 / 0.100 L = 1.05
moles in 20.0 mL = 1.05 M x 0.0200 L = 0.0216
New concentration = 0.0216 /0.500 L = 0.0432 M
moles in 100 mL = 0.100 L x 0.0432 = 0.00432
mass = 0.00432 x 180 g/mol= 0.778 g</span>