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Brilliant_brown [7]

3 years ago

12

these elements are the least likely to become involved in chemical reaction a) alkali metals b) halogens c) noble gases d) trans

ition metals e) rare earth metals

2 answers:

VikaD [51]3 years ago

8 0

Noble gases hardly ever participate in chemical reactions because they already have 8 valence electrons and are the most stable among other elements.

Therefore, C. noble gases is the correct answer.

Hope this would help~

Ksivusya [100]3 years ago

3 0

Noble Gases because their outer ring of electrons is full. Their full outer ring make it harder for the electrons to pull apart because their charge keeps them closer together.

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If an atom has a mass number of 23, which of the following is always true?

lesantik [10]

Atomic number is less than 11

8 0

3 years ago

at what temperature in celsius would a gas have volume of 13.5 L at a pressure of 0.723 atm, if it had a volume of 17.8 L at a p

Alex

Answer:

initial temperature= $-3.31^{\circ}C$

Explanation:

Assuming that the given follows the ideal gas nature;

$P_1=0.723atm$

$V_1=13.5L$

$T_1=?$

$P_2=0.612atm$

$V_2=17.8L$

$T_2=28 ^{\circ}C =273+28K=301K$

mole of gass will remain same at any emperature:

$\frac{P_1V_1}{T_1} =\frac{P_2V_2}{T_2}$

putting all the value we get:

$T_2 =269.7K =-3.31 ^{\circ} C$

initial temperature= $-3.31^{\circ}C$

6 0

3 years ago

A certain compound of bromine and fluorine is used to make UF6, which is an important chemical in the processing and reprocessin

Aleksandr [31]

Answer: The empirical formula is $BrF_3$

Explanation:

If percentage are given then we are taking total mass is 100 grams.

So, the mass of each element is equal to the percentage given.

Mass of Br= 58.37 g

Mass of F = (100-58.37) = 41.63 g

Step 1 : convert given masses into moles.

Moles of Br= $\frac{\text{ given mass of Br}}{\text{ molar mass of Br}}= \frac{58.37g}{80g/mole}=0.73moles$

Moles of F = $\frac{\text{ given mass of H}}{\text{ molar mass of H}}= \frac{41.63g}{19g/mole}=2.2moles$

Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.

For Br = $\frac{0.73}{0.73}=1$

For F = $\frac{2.2}{0.7}=3$

The ratio of Br: F= 1 : 3

Hence the empirical formula is $BrF_3$

8 0

2 years ago

For the first order process: AB The half-life of A is 62.1 seconds. If a sample of A initially has 250.0 g, what mass (in g) of

Molodets [167]

<u>Answer:</u> The mass of sample A after given time is 99.05 g.

<u>Explanation:</u>

All the radioactive reactions follows first order kinetics.

The equation used to calculate half life for first order kinetics:

$t_{1/2}=\frac{0.693}{k}$

We are given:

$t_{1/2}=62.1s$

Putting values in above equation, we get:

$k=\frac{0.693}{62.1}=0.011s^{-1}$

Rate law expression for first order kinetics is given by the equation:

$k=\frac{2.303}{t}\log\frac{[A_o]}{[A]}$

where,

k = rate constant = $0.011s^{-1}$

t = time taken for decay process = 84.2 s

$[A_o]$ = initial amount of the reactant = 250 g

[A] = amount left after decay process = ?

Putting values in above equation, we get:

$0.011s^{-1}=\frac{2.303}{84.2s}\log\frac{250}{[A]}$

$[A]=99.05g$

Hence, the mass of sample A after given time is 99.05 g.

5 0

3 years ago

The accepted value is 1.43. Which correctly describes this student’s experimental data?

Natalija [7]

Answer:

Neither accurate nor precise

Explanation:

The values were not near or even the same as the accepted value thus making it neither accurate nor precise.

4 0

3 years ago

Read 2 more answers