To solve this, we can use two equations.
t1/2 = ln 2 / λ = 0.693 / λ - (1)
where, t1/2 is half-life and λ is the decay constant.
Nt = Nοe∧(-λt) - (2)
Nt = amount of atoms at t =t time
Nο = initial amount of atom
t = time taken
From (1),
10 yr = 0.693 / λ
λ = 0.693 / 10 yr
From (2)
Nt = 100 g eΛ(-(0.693 / 10 yr) x 20 yr)
Nt = 25.00 g.
Hence, remaining mass will be 25.00 g
Answer:
1. solid and liquid
2.Evaporation changes liquid water to water vapour.
× atoms are in 0.0015 mol of fluorine gas
<h3>
What is fluorine?</h3>
The chemical element fluorine has an atomic number of 9 and the symbol F. The lightest halogen, it is an extremely poisonous, pale yellow diatomic gas under normal conditions. With the exception of argon, neon, and helium, it reacts with every other element, making it the most electronegative and reactive element.
Fluorine is the 24th most abundant element overall and the 13th most abundant on Earth. When added to metal ores to decrease their melting temperatures for smelting, fluorite, the main mineral source of fluorine that gave the element its name, was first recorded in 1529. The Latin word fluo, which means "flow," gave the mineral its name.
Learn more about fluorine
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Answer:
Melting is a physical change with no change in temperature of the substance while when the object is set on fire, its temperature changes.
Explanation:
Melting cause physical change in any substance. The temperature of the substance remain same but the physical property changes i.e in melting substance changes its state from solid to liquid.
However, in case of setting a substance on fire the temperature changes along with the state of the substance.
Answer:
Because the neutrons equal the number of protons
Explanation:
So if u have 16 protons u have 16 neutrons