The amount of sample that is left after a certain period of time, given the half-life, h, can be calculated through the equation.
A(t) = A(o) (1/2)^(t/d)
where t is the certain period of time. Substituting the known values,
A(t) = (20 mg)(1/2)^(85.80/14.30)
Solving,
A(t) = 0.3125 mg
Hence, the answer is 0.3125 mg.
They depend on nitrogen-fixing bacteria, which convert atmospheric nitrogen into a usable form.
Photosynthesis is the process where plants create energy. It requires water, carbon dioxide and sunlight. The end result is glucose, which the plants consume, and oxygen. Cellular respiration requires oxygen and glucose. The end result is carbon dioxide, ATP, and water.
Answer:
49.86 × 10²³ atoms of Al
Explanation:
Given data:
Number of moles of Al = 8.28 mol
Number of atoms = ?
Solution:
The given problem will solve by using Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.
The number 6.022 × 10²³ is called Avogadro number.
For example,
18 g of water = 1 mole = 6.022 × 10²³ molecules of water
1.008 g of hydrogen = 1 mole = 6.022 × 10²³ atoms of hydrogen
For 8.28 moles of Al:
1 mole = 6.022 × 10²³ atoms of Al
8.28 mol×6.022 × 10²³ atoms / 1mol
49.86 × 10²³ atoms of Al
The designation "4" before Na2SO3 simply means that there are four molecules of sodium sulfite.
A molecule is formed when two or more atoms of the same or different elements come together. The formula of the molecule must reflect the number of atoms from which it is formed. The designation "4" before Na2SO3 simply means that there are four molecules of sodium sulfite.
The "The World on Turtle's Back" is a legend creation story. According to this story, the world was created on a giant turtle back. The folktale is common among the Iroquois Native Americans.
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