Answer:
40.7% abundance of Ga-71
59.93% abundance of Ga-69
Explanation:
Given data:
Average atomic mass of Ga = 69.72 amu
Atomic mass of Ga-69 = 68.9257 amu
Atomic mass of Ga-71 = 70.908 amu
Percent abundance of each isotope = ?
Solution;
we know there are two naturally occurring isotopes of Ga.
First of all we will set the fraction for both isotopes
X for the isotopes having mass 68.9257
1-x for isotopes having mass 70.908
we will use the following equation,
68.9257x + 70.908
(1-x) = 69.72
68.9257x +70.908 - 70.908x = 69.72
68.9257x - 70.908x = 69.72 - 70.908
-1.9823x = - 1.188
x= 1.188/1.9823
x= 0.5993
0.5993 × 100 = 59.93 %
59.93 % is abundance of Ga-69 because we solve the fraction x.
now we will calculate the abundance of Ga-71.
(1-x)
1 - 0.5993 = 0.4007
0.4007× 100= 40.7 %
40.7 % for Ga-71.
Answer:
B?
Explanation:
In the example, the amount of hydrogen is 202,650 x 0.025 / 293.15 x 8.314472 = 2.078 moles. Use the mass of the hydrogen gas to calculate the gas moles directly; divide the hydrogen weight by its molar mass of 2 g/mole. For example, 250 grams (g) of the hydrogen gas corresponds to 250 g / 2 g/mole = 125 moles.
<h3>
Answer:</h3>
Fe₂O₃(s) + 3CO(g) → 2Fe(s) + 3CO₂(g)
<h3>
Explanation:</h3>
Concept tested: Balancing of chemical equations
- A chemical equation is balanced by putting appropriate coefficients on the products and reactants of the equation.
- Balancing chemical equations ensures that chemical equations obey law of conservation of mass.
- In this case; to balance the above equation we put the coefficients, 1, 3, 2, and 3 on the reactants and products.
- Therefore; the balanced chemical equation for the reaction is;
Fe₂O₃(s) + 3CO(g) → 2Fe(s) + 3CO₂(g)
C. Magma from venus mantle erupted as lava.
Explanation:
A volcano is a land form which results from the eruption of molten rocks (lava) on the surface. Volcanic rocks are a special type of igneous rock that forms when molten rock cools and solidifies on the surface.
For a planet like Venus which is presently not active and little to no movement occurs within the plates, the volcanisim must have occurred when the planet was relatively young and it must have been millions of years ago.
It is widely believed that Venus was geologically active in times past. Mantle generated lava must have solidified on the surface in times past to have formed the volcano.
Evaluating other options:
Impact of space objects on Venus would lead to the formation of a crater which is a depression on the surface. The rock would be mostly metamorphic.
If water was ever present in Venus, they would have produced sedimentary rocks instead. The erosive power of water is not high enough to cut through the crust. Also, water would not aid the formation of volcanoes.
Heat is not enough to from volcanoes. Other factors are also in play.
The correct answer is A, Volume
