Answer: A) 0.0480 grams and B) 56.16 years.
Explanation: Half live is the time in which the amount of radioactive substance remains halve of its initial amount.
The formula we use for solving this type of problem is:

where,
is the initial amount and N is the remaining amount of radioactive substance and n is the number of half lives.

where, T is the time and
is half life.
A) from given data,
= 2 g
T = 70 years
= 13 years
N= ?

n = 5.38


N = 0.0480 g
So, 0.0480 grams of the substance will be remaining after 70 years.
B)
= 2 g
N = 0.1 g
T = ?
Let's first calculate the value of n for this.


Taking log to both sides:



n = 4.32
Half life is 13 years, so we can calculate the time as:



T = 56.16 years
So, it will take 56.16 years for the radioactive substance to decay from 2 g to 0.1 g.
Intensive properties are useful for identifying a substance simply because these properties do not depend on the amount of sample, nor do they change according to conditions.
The correct answer choice which is a physical property of matter is boiling point.
Polymers are long chains of <u>molecules</u>
The method which I would use to separate two liquids with different boiling points is <u>distillation</u>
The particles are located in the nucleus of an atom are protons and neutrons
The type of molecular model which is used to represent very large molecules like proteins is ribbon diagram
The methods which is used to separate a mixture according to the size of the particles are filtration and chromatography
<h3>What is a mixture?</h3>
A mixture is a substance which contains two or more constituents which can easily be separated by physical means
So therefore, the methods which is used to separate a mixture according to the size of the particles are filtration and chromatography
Learn more about mixtures:
brainly.com/question/2331419
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The answer is: 8.14·10⁶³ moles of lithium are present.
N(Li₂SO₄) = 2.45·10⁸⁷; number of formula units of lithium sulfate.
n(Li₂SO₄) = N(Li₂SO₄) ÷ Na.
n(Li₂SO₄) = 2.45·10⁸⁷ ÷ 6.022·10²³ 1/mol.
n(Li₂SO₄) = 4.07·10⁶³ mol; amount of lithium sulfate
In one molecule of lithium sulfate, there are two atoms of lithium.
n(Li₂SO₄) : n(Li) = 1 : 2.
n(Li) = 2 · 4.07·10⁶³ mol.
n(Li) = 8.14·10⁶³ mol; amount of lithium atoms.
Answer:
The specific heat (\(c_s\)) of a substance is the amount of energy needed to raise the temperature of 1 g of the substance by 1°C, and the molar heat capacity (\(c_p\)) is the amount of energy needed to raise the temperature of 1 mol of a substance by 1°C. Liquid water has one of the highest specific heats known.
Explanation: