What are the four important steps needed to obtain accurate meting points on a Mel-Temp?

Chemistry

1 answer:

Debora [2.8K]3 years ago

4 0

Answer: (b)

(d)

(e)

(g)

Explanation:

The four (4) important steps that are needed to obtain an accurate melting point is given as;

• First is Grinding: Grind the sample into fine powder.

• Second is Filling: Fill the capillary tube with about 3mm of powder

• Third is Adjusting the temperature: Set the voltage to rise quickly to 20° below the expected temperature, then re-adjust so the temperature rises at 2° per minute.

• Lastly is Observation and recordings: Record the temperature the temperature at which liquid first appears and the temperature at which the last crystal disappears.

I hope this helps, cheers.

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Which of the following is a geographic example of a transform fault boundary?

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A plutonium atom undergoes nuclear fission. Identify the missing element in the nuclear equation.

horrorfan [7]

Answer:

$_{92}^{226}U$

Explanation:

Let's firstly identify the atomic number (the number of protons) of Pu. This is done by referring to the periodic table and finding Pu. The atomic number of Pu is:

$Z=94$

In order to identify the type of a nuclear decay, we need to find the N/Z ratio. This is the ratio between the number of neutrons and the atomic number of an isotope. The number of neutrons is found by subtracting the number of protons from the mass number:

$N=M-Z$

That said, the N/Z ratio equation becomes:

$N/Z=\frac{M-Z}{Z}=\frac{M}{Z}-1=\frac{230}{94}-1=1.45$

This is a relatively high number thinking about the belt of stability of isotopes. Ideally, stable isotopes with a low Z value have an N/Z ratio of 1. Heavier isotopes with Z > 50 would have a slightly higher N/Z ratio and would be stable around N/Z = 1.25. This means we wish to decrease the N/Z ratio as much as possible.

Among all the decays, alpha-decay is preferred to decrease the N/Z ratio significantly (1.45 is much higher than 1.25). That said, we'll release an alpha particle with some nucleotide X of mass M and atomic number Z:

$_{94}^{230}Pu\rightarrow _Z^MX+_2^4\alpha$