All categories

2 years ago

Uses of noble gases with description please. thanks

1 answer:

6 0

The elements in this group are helium, neon, argon, krypton, xenon, and radon. They are monatomic gases. ... They are extremely rare in nature, and none was known until helium was discovered to exist on the sun. In fact, the name of the element helium was derived from the Greek word Helios, used to refer to the sun.

You might be interested in

Which of these elements exhibits chemical behavior similar to that of oxygen? select one:

scoray [572]

Answer:
Sulfur (Option-C) exhibits chemical behavior similar to that of oxygen.

Explanation:
Sulfur has same chemical properties as that of Oxygen because both of them belongs to same group in the periodic table. Also, the similarity of chemical behaviour among the group members is due to same number of electrons in their valence shells.
For examole, the electronic configuration of Oxygen is,

1s², 2s², 2p⁴

There are six valence electrons in the valence shell (i.e. 2) of Oxygen.

Now for Sulfur,
1s², 2s², 2p⁶, 3s², 3p⁴

There are six valence electrons in the valence shell (i.e. 3) of Sulfur.

Therefore, both elements tends to gain 2 electrons in a reaction and form O⁻² and S⁻² respectively.

3 0

3 years ago

Which statement best describes an array of 10 elements where the elements are of a class type?

ladessa [460]

The array will be created with the elements equal to null.

3 0

2 years ago

Toluene (C6H5CH3 ), an organic compound often used as a solvent in paints, is mixed with a similar organic compound, benzene (C6

Sergeeva-Olga [200]

Explanation:

The given data is as follows.

Weight of solute = 75.8 g, Molecular weight of solute (toulene) = 92.13 g/mol, volume = 200 ml

Therefore, molarity of toulene is calculated as follows.

Molarity = $\frac{\text{weight of solute}}{\text{molecular weight of solute}} \times \frac{1000}{\text{volume of solution in ml}}$

= $\frac{75.8 g}{92.13 g/mol} \times \frac{1000}{200 ml}$

= 4.11 M

Hence, molarity of toulene is 4.11 M.

As molality is the number of moles of solute present in kg of solvent.

So, we will calculate the molality of toulene as follows.

Molality = $\frac{\text{given weight of solute}}{\text{given molecular weight of solute}} \times \frac{1000}{\text{weight of solvent in grams}}$

= $\frac{75.8 g}{92.13 g/mol} \times \frac{1000}{95.6 g}$

= 8.6 m

Hence, molality of given toulene solution is 8.6 m.

Now, calculate the number of moles of toulene as follows.

No. of moles = $\frac{mass}{\text{molar mass}}$

= $\frac{75.8 g}{92.13 g/mol}$

= 0.8227 mol

Now, no. of moles of benzene will be as follows.

No. of moles = $\frac{mass}{\text{molar mass}}$

= $\frac{95.6 g}{78.11 g/mol}$

= 1.2239 mol

Hence, the mole fraction of toulene is as follows.

Mole fraction = $\frac{\text{moles of toulene}}{\text{total moles}}$

= $\frac{0.8227 mol}{(0.8227 + 1.2239) mol}$

= 0.402

Hence, mole fraction of toulene is 0.402.

As density of given solution is 0.857 $g/cm^{3}$ so, we will calculate the mass of solution as follows.

Density = $\frac{mass}{volume}$

0.857 $g/cm^{3}$ = $\frac{mass}{200 ml}$ (As 1 $cm^{3}$ = 1 g)

mass = 171.4 g

Therefore, calculate the mass percent of toulene as follows.

Mass % = $\frac{\text{mass of solute}}{\text{mass of solution}} \times 100$

= $\frac{75.8 g}{171.4 g} \times 100$

= 44.22%

Therefore, mass percent of toulene is 44.22%.

8 0

3 years ago

Explain, in terms of electrons, why the bonding in strontium sulfide, SrS, is similar to the bonding in magnesium bromide, MgBr2

Aleksandr-060686 [28]

Answer: both compounds have ionic bond between metal and non-metal

Explanation: both Sr and Mg are earth alkaline metals and form ions Mg^2+

And Sr^2+. Br forms ion Br^- and S ion is S^2+.

5 0

2 years ago

Draw a schematic of the hydrogen atom with the single proton in the nucleus, and the n=1, n=2, n=3, and n=4 energy level options

max2010maxim [7]

Explanation:

According to Bohr's postulates, the electron in the present in the lower energy level can absorb energy and exits to higher energy level. Also, when this electron returns back to its orbit, it emits some energy.

Since the hydrogen consists of 1 electron and 1 proton. The lowest energy configuration of the hydrogen is when n =1 or, when the electron is present in the K-shell or the ground state.

The possible transition for the electron given in the question is :

n = 2, 3 and 4

The schematic diagram of the hydrogen atom consisting of these four quantum levels in which the electron can jump (Absorption) and comeback to from these energy levels (emission) .

3 0

3 years ago