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jeyben [28]
3 years ago
15

Need help with this science question............

Chemistry
1 answer:
Brums [2.3K]3 years ago
4 0

Answer:

18- H

19- D

20-G

21-A

(i think these are the answers)

Explanation:

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Which of the following is the best example of a scientific law?
il63 [147K]

Answer:

The correct answer is :'The gravitational force between two objects is related mathematically to their mass and the distance between them'.

Explanation:

A scientific law is a statement which explains physical phenomena and has been tested multiple times through the correct scientific methods and experimentation. It will give same results and observations after each conduct.

A scientific law comes into picture after the acceptance of a theory which explains or exposes the reason behind any physical phenomena occurrence.

So the best example of scientific law:

The gravitational force between two objects is related mathematically to their mass and the distance between them.

5 0
3 years ago
Read 2 more answers
Any substance that when dissolved in water will give off h ions is referred to as a(n) ________.
-BARSIC- [3]
Its is definitely an acid
3 0
3 years ago
Americium-241 is used in smoke detectors. it has a first order rate constant for radioactive decay of k=1.6×10−3yr−1. by contras
Helga [31]
This question is missing the part that actually asks the question. The questions that are asked are as follows:

(a) How much of a 1.00 mg sample of americium remains after 4 day? Express your answer using 2 significant figures.

(b) How much of a 1.00 mg sample of iodine remains after 4 days? Express your answer using 3 significant figures.

We can use the equation for a first order rate law to find the amount of material remaining after 4 days:

[A] = [A]₀e^(-kt)

[A]₀ = initial amount
k = rate constant
t = time
[A] = amount of material at time, t.

(a) For americium we begin with 1.00 mg of sample and must convert time to units of years, as our rate constant, k, is in units of yr⁻¹.

4 days x 1 year/365 days = 0.0110

A = (1.00)e^((-1.6x10^-3)(0.0110))
A = 1.0 mg

The decay of americium is so slow that no noticeable change occurs over 4 days.

(b) We can simply plug in the information of iodine-125 and solve for A:

A = (1.00)e^(-0.011 x 4)
A = 0.957 mg

Iodine-125 decays at a much faster rate than americium and after 4 days there will be a significant loss of mass.
7 0
3 years ago
Please show all of your work! :)
Paladinen [302]

Answer:

A

Explanation:

To answer this, we need to use Gay-Lussac's law, which states that:

\frac{P_1}{T_1}= \frac{P_2}{T_2} , where P is pressure and T is temperature

The initial pressure we're given is 4.5 atm (so P1 = 4.5) and the temperature is 45.0°C; however, we need to change Celsius to Kelvins, so add 273 to 45.0: 45.0 + 273 = 318 K (so T1 = 318).

The final pressure is what we want to find, but we do know the final temperature is 3.1°C. Converting this to Kelvins, we get: 3.1 + 273 = 276.1 K, which means T2 = 276.1.

Plug these values in:

\frac{P_1}{T_1}= \frac{P_2}{T_2}

\frac{4.5}{318}= \frac{P_2}{276.1}

Multiply both sides by 276.1:

P_2 ≈ 3.9 atm

The answer is thus A.

3 0
3 years ago
What are the different rows called
ser-zykov [4K]
Vertical-horizon.
If neither of them are it then it’s columns
7 0
3 years ago
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