Answer:
6.73g
Explanation:
T½ = 5.2days
No = 80g
N = ?
T = 20.8days
We'll have to find the disintegration constant first so that we can plug it into the equation that will help us find the mass of the sample after 20.8 days
T½ = In2 / λ
T½ = half life
λ = disintegration constant
λ = In2 / T½
λ = 0.693 / 5.8
λ = 0.119
In(N / No) = -λt
N = final mass of the radioactive sample
No = initial mass of the sample
λ = disintegration constant
t = time for the radioactive decay
In(N/No) = -λt
N / No = e^-λt
N = No(e^-λt)
N = 80 × e^-(0.119 × 20.8)
N = 80 × e^-2.4752
N = 80 × 0.0841
N = 6.728g
The mass of the sample after 20.8 days is approximately 6.73g
Answer:
See explanation
Explanation:
Microwaves work by flipping water molecules upside down, then right side up again, and so on at very high speeds, and the friction generates heat. Some glass or plastic isn't affected by the microwaves, so the molecules don't get flipped, and so no friction occurs and no heat is produced, leading to the dish not being heated up.
Answer: Compound . Chemical reactions can divide elements into simpler substances, but they cannot separate elements into simpler substances. Physical or chemical characteristics of substances can be categorised.
Compounds and elements can be created from pure substances. A chemical reaction is required to break down pure substances (elements and compounds) into their component atoms or elements. This is known as the chemical separation process. Physical separation of pure substances is impossible.
Explanation:
What makes something pure substance?
One element or a small number of related compounds make up pure substances. Mixtures are assemblages of many components. Mixtures of two or more substances (or elements) that cannot be visually distinguished from one another are referred to as homogeneous mixtures.
What sort of compound would that be?
A substance made up of two or more components is called a compound. Table salt, water, and carbon dioxide are a few examples of compounds
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