Which of the following is formed when a barium atom achieves an octet?

Elaborate on how to classify elements and pure compounds.

tankabanditka [31]

Answer: C) Elements and pure compounds are homogeneous materials because they have a uniform composition throughout.

Explanation: Element is a pure substance which is composed of atoms of similar elements. Compound is a pure substance which is made from atoms of different elements combined together in a fixed ratio by mass.

Elements are compounds form homogeneous materials as they have uniform composition throughout and the components are evenly distributed throughout the material.

Mixtures are heterogeneous materials as they do not have uniform composition and the components are not evenly distributed throughout the material.

4 0

3 years ago

Read 2 more answers

Determine whether each statement describes an electromagnetic wave, a mechanical wave, or both types of wave.

KiRa [710]

The question is incomplete, the complete question is;

Which statement describes a difference between electromagnetic and mechanical waves?

A. Mechanical waves cannot be longitudinal, but electromagnetic waves can.

B. Electromagnetic waves cannot move particles, but mechanical waves can.

C. Electromagnetic waves do not require a medium, but mechanical waves do.

D. Mechanical waves do not transfer energy, but electromagnetic waves do.

Answer:

Electromagnetic waves do not require a medium, but mechanical waves do.

Explanation:

A wave is defined as a disturbance along a medium which transfers energy. Waves may be classified as mechanical waves or electromagnetic waves based on their medium of propagation.

A mechanical wave requires a material medium for propagation. An example of a mechanical wave is sound waves. Sound waves are propagated in air.

Electromagnetic waves do not require a material medium for propagation. They can travel through space. An example of electromagnetic waves is light waves.

8 0

3 years ago

mixture of 75 cm3of oxygen and 12.5 cm3 of a gaseous hydrocarbon H were exploded in an eudiometer. After cooling to room tempera

Mrac [35]

Answer:

molar mass of C₃H ₈ = 44 g/mole

Explanation:

Computation of the amount of oxygen that reacts .

⇒ 75 - 12.5

⇒ 62.5 cm³

Computation of proportion of hydrocarbons

2 mole hydrocarbons 3n+1 oxygen

⇒ 3 n + 1 = [62.5 × 2] / 12.5

⇒ 3 n + 1 = 10

⇒ n = 3

So,

Formula of the hydrocarbon is C₃H ₈

Computation of molar mass of C₃H ₈

⇒ [12×3] + [1×8]

⇒ 44 g/mole

8 0

2 years ago

Scientists discovered that earths core has two parts by studying?

Tatiana [17]

Answer:

its not actually proven its just a hypothesis because they can't dig that deep because of the pressure

8 0

2 years ago

The formation constant for the following reaction is Kf = 5.6 108 at 25°C. Ni2+(aq) + 6 NH3(aq) Ni(NH3)62+(aq) (a) Determine G0

marusya05 [52]

Answer:

a. ΔG⁰ = -49.9 kJ/mol

b. The reaction proceeds towards right direction

c. ΔG = 49.5 kJ/mol

d. The reaction proceeds towards left direction

Explanation:

a. It is possible to obtain ΔG⁰ from K reaction using:

ΔG⁰ = -RT ln K

Where R is gas constant 8.314 J/molK, T is absolute temperature (273.15 +25 = 298.15K)

Replacing:

ΔG⁰ = -8.314 J/molK 298.15K ln 5.6x10⁸

ΔG⁰ = -49.9 kJ/mol

b. Reaction quotient Q, defines concentrations of substances involved in an equilibrium, when Q = Kf, the reaction is in equilibrium, when Q < Kf the reaction moves towards right direction and vice versa.

At standard-state concentrations, Q = 1, as:

Q < Kf, the reaction proceeds towards right direction

c. ΔG = ΔG⁰ + RT ln Q

Q = [Ni(NH₃)₆²⁺] / [NH₃]⁶[Ni²⁺]

Q = 0.017M / 0.0015M⁶×0.0058M

Q = 2.6x10¹⁷

ΔG = -49.9 kJ/mol + 8.314x10⁻³ kJ/molK 298.15K ln 2.6x10¹⁷

ΔG = 49.5 kJ/mol

d. As Q > Kf, the reaction proceeds towards left direction

7 0

3 years ago