I need hellppp please.

Atoms of two different elements must have different

kogti [31]

Answer:

C atomic number

Explanation:

As u go from left to right the atomic number changes

So C is the answer,

I took the test on edge and that was the answer

3 0

3 years ago

Based on the periodic table, which of the following elements has properties most like neon’s?

ohaa [14]

Answer:

<h2>D. Krypton (Kr)</h2>

<u>Explanation:</u>

because

Neon and Krypton, both are belongs to Inert or Noble gas Group

3 0

3 years ago

Read 2 more answers

Someone plz help me :(

sleet_krkn [62]

c.

Explanation:

I mainly think its c. from my point of view because as yoy can see they showed observations and explained certain information and they didnt conclude it as it's TRUE they said theories meaning its and Idea and something that is not fully proven happend.

6 0

3 years ago

A Metal pan will heat up quickly when placed over a gas or electric burner. The Metal pan is a good what...

Alik [6]

Answer:

heating up, lol

Explanation:

8 0

3 years ago

Hydrogen fluoride is used in the manufacture of Freons (which destroy ozone in the stratosphere) and in the production of alumin

Lerok [7]

<u>Answer:</u> The percentage yield of HF is 73.36 %

<u>Explanation:</u>

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$ ....(1)

For calcium fluoride:

Given mass of calcium fluoride = 6.25 kg = 6250 g (Conversion factor: 1 kg = 1000 g)

Molar mass of calcium fluoride = 78.07 g/mol

Putting values in above equation, we get:

$\text{Moles of calcium fluoride}=\frac{6250g}{78.07g/mol}=80.05mol$

For the given chemical reaction:

$CaF_2+H_2SO_4\rightarrow CaSO_4+2HF$

By Stoichiometry of the reaction:

1 mole of calcium fluoride produces 2 moles of hydrofluoric acid

So, 80.05 moles of calcium fluoride will produce = $\frac{2}{1}\times 80.05=160.1mol$ of hydrofluoric acid

Now, calculating the theoretical yield of hydrofluoric acid using equation 1, we get:

Moles of of hydrofluoric acid = 160.1 moles

Molar mass of hydrofluoric acid = 20.01 g/mol

Putting values in equation 1, we get:

$160.1mol=\frac{\text{Theoretical yield of hydrofluoric acid}}{20.01g/mol}=3203.6g=3.20kg$

To calculate the percentage yield of hydrofluoric acid, we use the equation:

$\%\text{ yield}=\frac{\text{Experimental yield}}{\text{Theoretical yield}}\times 100$

Experimental yield of hydrofluoric acid = 2.35 kg

Theoretical yield of hydrofluoric acid = 3.20 kg

Putting values in above equation, we get:

$\%\text{ yield of hydrofluoric acid}=\frac{2.35g}{3.20g}\times 100\\\\\% \text{yield of hydrofluoric acid}=73.36\%$

Hence, the percentage yield of HF is 73.36 %

4 0

3 years ago