Answer:
See the answer below
Explanation:
<u>The percentage by mass of a substance in a mixture is the ratio of the mass of the substance and the mass of the entire mixture.</u>
<em>Hence, when concentrated HNO3 is said to be 69% by mass of nitric acid, it means that the solution of the acid has 69% HNO3 and 31% water in terms of mass. More specifically, 100 g of the solution of the acid would contain 69 g of HNO3 and 31 g of water respectively,</em>
Answer:
Graphite (/ˈɡræfaɪt/), archaically referred to as plumbago, is a crystalline form of the element carbon with its atoms arranged in a hexagonal structure. It occurs naturally in this form and is the most stable form of carbon under standard conditions. ... Graphite is used in pencils and lubricants.
Answer:
b
Explanation:
because it is products /reactants :)
Answer:
11.9g remains after 48.2 days
Explanation:
All isotope decay follows the equation:
ln [A] = -kt + ln [A]₀
<em>Where [A] is actual amount of the isotope after time t, k is decay constant and [A]₀ the initial amount of the isotope</em>
We can find k from half-life as follows:
k = ln 2 / Half-Life
k = ln2 / 27.7 days
k = 0.025 days⁻¹
t = 48.2 days
[A] = ?
[A]₀ = 39.7mg
ln [A] = -0.025 days⁻¹*48.2 days + ln [39.7mg]
ln[A] = 2.476
[A] = 11.9g remains after 48.2 days
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