A volleyball contains 1.36 g of nitrogen gas. How many moles of N2 gas are in the volleyball?

Sort these species into isoelectronic groups. It doesn\'t matter which group goes in which box, so long as the correct species a

OleMash [197]

Answer : The isoelectronic groups are:

$He,Be^{2+},Li^{+}$

$N^{3-},Mg^{2+}$

$S^{2-},Ti^{4+},K^{+}$

Explanation :

Isoelectronic : It is defined as the compound or molecule having the same number of electrons and the same number of electronic structure.

The element is helium. The number of electrons are 2.
The element is beryllium. The number of electrons are 4. The number of electrons in $Be^{2+}$ = 4 - 2 = 2
The element is lithium. The number of electrons are 3. The number of electrons in $Li^{+}$ = 3 - 1 = 2
The element is nitrogen. The number of electrons are 7. The number of electrons in $N^{3-}$ = 7 + 3 = 10
The element is neon. The number of electrons are 10.
The element is sulfur. The number of electrons are 16. The number of electrons in $S^{2-}$ = 16 + 2 = 18
The element is magnesium. The number of electrons are 12. The number of electrons in $Mg^{2+}$ = 12 - 2 = 10
The element is titanium. The number of electrons are 22. The number of electrons in $Ti^{4+}$ = 22 - 4 = 18
The element is potassium. The number of electrons are 19. The number of electrons in $K^{+}$ = 19 - 1 = 18

The isoelectronic groups are:

$He,Be^{2+},Li^{+}$

$N^{3-},Mg^{2+}$

$S^{2-},Ti^{4+},K^{+}$

7 0

3 years ago

1. All of the following energy resources are fossil fuels except

solong [7]

C. Biomass is the correct answer

4 0

3 years ago

Why does magnesium oxide have a high melting point?

Mandarinka [93]

Magnesium oxide is an ionic compound ( because it consists of a metal and a non-metal)

In ionic compounds, electrons from the outer shell exchange between the atoms so that they each get a full outer shell. Once these electrons are exchange, the atoms will become ions. One ion will have a positive charge, and the other ion will have a negative charge. The positive and negative ions then bond strongly together in a lattice structure, due to the <u>electrostatic forces of attraction</u>.

These <u>electrostatic forces of attraction</u> are very strong and require a lot of energy to break, as such the compound will have <u>a high melting point</u>.

__________________________________________

Now lets look at the ionic bonding between magnesium and oxygen:

In the outer shell of Magnesium, there are 2 electrons.

In the outer shell Oxygen, there are 6 electrons.

Magnesium gives it's two electrons to Oxygen, so that the Oxygen now has a full outer shell of 8 electrons. However, since Oxygen gained two electrons, it will form a negatively charged ion with a charge of -2.

Since Magnesium lost the two electrons, it's second shell (which has 8 eletrons) now becomes the outer shell. So Magnesium also now has a full outer shell. But since it has lost two electrons, it becomes a positively charged ion with a charge of + 2.

The positive Magnesium ion and negative Oxygen ion and now strongly attracted to each other, and form a strong ionic compound (magnesium oxide) with a lattice structure.

The <u>electrostatic forces of attraction</u> between the positive Magnesium and negative Oxygen are so strong that <u>a lot of heat and energy are needed to break them</u>.

<u>Therefore magnesium oxide has a high melting point.</u>

5 0

3 years ago

Indicate whether each of the following would increase or decrease the rate of reaction

mote1985 [20]

The rate of a chemical reaction is affected by temperature, Catalysts, Suface area, Concentration.

<h3>Rate of reaction</h3>

The rate of a chemical reaction is the rate at which the concentration of reactant molecules decreases or the concentration of product molecules increases.

<h3>Factors effecting rate of chemical reaction </h3>

The factors that affect the rate of chemical reaction include:

Temperature: increase in temperature increases reaction rate while decrease in temperature decreases reaction rate.
Catalysts: the present of catalysts increase the reaction rate. Some catalysts decreases reaction rate and are known as negative catalysts.
Surface area: increase in surface area of reactants increases reaction rate.
Concentration: Increase in concentration of reactants increases reaction rate while decrease in concentration of reactants decreases reaction rate.

Therefore, the rate of a chemical reaction is affected by temperature, Catalysts, Suface area, Concentration.

Learn more about rate of reaction and factors affecting reaction rate at: brainly.com/question/15841605

7 0

2 years ago

A student titrated 25.0 cm3 portions of dilute sulfuric acid with a 0.105 mol/dm3 sodium hydroxide solution.The equation for the

Rzqust [24]

Answer:

This question is incomplete

Explanation:

This question is incomplete as the volume of the base that was used during the titration was not provided. However, the completed question is in the attachment below.

The formula to be used here is CₐVₐ/CbVb = nₐ/nb

where Cₐ is the concentration of the acid = unknown

Vₐ is the volume of the acid used = 25 cm³ (as seen in the question)

Cb is the concentration of the base = 0.105 mol/dm³ (as seen in the question)

Vb is the volume of the base = 22.13 cm³ (22.1 + 22.15 + 22.15/3)

nₐ is the number of moles of acid = 1 (from the chemical equation)

nb is the number of moles of base = 2 (from the chemical equation)

Note that the Vb was based on the concordant results (values within the range of 0.1 cm³ of each other on the table) of the student

Cₐ x 25/0.105 x 22.13 = 1/2

Cₐ x 25 x 2 = 0.105 x 22.13 x 1

Cₐ x 50 = 0.105 x 22.13

Cₐ = 0.105 x 22.13/50

Cₐ = 0.047 mol/dm³

The concentration of the sulfuric acid is 0.047 mol/dm³

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7 0

3 years ago