The density of a metal cube is 8 x103 kg/m3. Convert

Which of these elements is unlikely to have a reaction with any element or compound?

Kay [80]

Argon is a noble gas. Argon has a full outer shell. This makes it so that it does not need to react with any of the other elements to be stable.

With Rubidium and Cobalt its a whole different story.

I hope that helps!

8 0

3 years ago

Is it necessary to prepare sodium extract to detect nitrogen in urea ?

Vilka [71]

Answer:

I think No

Explanation:

7 0

2 years ago

If 3.89 × 1024 atoms of a noble gas is collected and it has a mass of of 848 grams, this element is most likely a. He b. Ne c. A

bearhunter [10]

Answer:

Xenon

Explanation:

Avogadro’s number represent the number of the constituent particles which are present in one mole of the substance. It is named after scientist Amedeo Avogadro and is denoted by $N_0$ .

Avogadro constant:-

$N_a=6.023\times 10^{23}$

Let the molar mass of the element is x g/mol

So,

$6.023\times 10^{23}$ atoms have a mass of x g

Also,

$3.89\times 10^{24}$ atoms have a mass of $\frac{x}{6.023\times 10^{23}}\times 3.89\times 10^{24}$ g

This mass is equal to 848 g

So,

$\frac{x}{6.023\times 10^{23}}\times 3.89\times 10^{24}=848$

x= 131.3 g/mol

This mass correspond to xenon.

3 0

3 years ago

Please do these questions, will give brainliest

Nata [24]

Answer:

1.c 2.a.3.d 4.a

Explanation:

that is tge answer

3 0

3 years ago

Could someone please care to explain what the answer is

polet [3.4K]

Calculate the percentage composition of Ca(MnO4)2.

<u>Firstly, we see how many atoms are there for each element in the formula</u>.

Ca= 1 atom

Mn= 2 atoms

O= 8 atoms

<u>Next, we are going to consult our periodic table for the atomic mass of each element.</u>

Ca= 40

Mn= 55

O= 16

Then, we have to find the molar mass for the compound..

Here is the formula for calculating molar mass of an element:

Molar Mass= ( no. of atoms of the element × atomic mass of the element)

Now, we have to calculate the atomic mass of the compound. So using the molar mass formula for an element, we calculate the molar mass for each element then we sum up their molar masses to get the compounds molar mass.

Molar mass (Ca)= 1× 40

(Ca)= 40

Molar mass (Mn)=2×55

(Mn)= 110

Molar mass (O)= 8×16

(O)= 128

Now: Molar mass( compound)= (Ca)+(Mn)+(O)

= 40+ 110 128

= 278

This is everything we need to calculate our percentage composition for each element..

* The example says to find the percentage composition for Ca. So we only find for Ca, Which is already done using the formula and the answer is 14.39%.

To prove that your answer is correct, find the percentage composition for Mn and O as well. Then you add up their percentage compositions.

If you do and you get 100 as your answer, then your percentage compositions are correct.

Why don't you try finding the percentage composition for Mn and O, then add up all the three percentage compositions. If you 100 as their sum, then your percentage composition for each of the elements are correct.

6 0

3 years ago