Magnesium burns with a very bright light. When the flame goes out, a White powder is left behind. what is the word equation for this reaction.

joules.......I hope this helps

Answer:

The correct answer is Option (2)- Burning up of fossil fuels

Explanation:

Fossils are the remnants of the ancient plants and animals that were buried millions of years ago. Those fuels that are made up of these fossilized matters are commonly termed as fossil fuel. For example, Petroleum, Coal and natural gas. These are the major source of energy.

These fossil fuels are limited in amount and are non-renewable sources of energy. These are exploited rapidly by human beings. This burning up of fossil fuels leads to the production of a large amount of Carbon dioxide (CO₂) gas that causes a significant impact on the atmosphere. The increase in the CO₂ content also leads to an increase in the global temperature of the earth.

In the last 100 years, the CO₂ level in the atmosphere has immensely increased.

Hence, the correct answer is option (2).

Answer:

               KBr (aq) is a mixture.

Explanation:

                       Mixture is defined as the combination of two non reacting species. Let's discuss each option one by one.

a) Br₂(l):

              This Bromine is not a mixture because the bracket specifying the state of Br₂ is liquid. Hence, as bromine is a liquid at room temperature, so this compound is purely Br₂.

b) KBr (s):

                KBr is also present in pure form because in bracket solid is written.

c) K (s):

              Potassium is also present in pure form as the bracket is specifying solid, as KBr is solid at room temperature.

d) KBr (aq):

                   This is a mixture of KBr and water. Because KBr being an electrolyte when dissolved in water it is hydrated as follow,

                             KBr (s) -----water------> K⁺ (aq) + Br⁻ (aq)

is a mixture.

Further explanation:

Mixture:

It is formed by the physical combination of two or more different substances. Mixtures do not have any fixed formula and their composition is also variable. There is retention in the properties of constituents even after the formation of mixtures.

(1)  

Bromine is present in liquid in its pure state. The “l” written in the parenthesis after   denotes its physical state which is the same as that of its pure form. So it is not a mixture.

(2) K (s)

Potassium is present in solid in its pure form. The “s” written in the parenthesis after K describes its physical state which is the same as that of its pure form. So it is not a mixture.

(3) KBr (s)

It is an ionic salt which is solid in nature. The “s” written in the parenthesis after KBr denotes its physical state which is the same as that of its pure form. So it is not a mixture.

(4) KBr (aq)

The “aq” written in the parenthesis after KBr indicates that it is present in the aqueous phase. This means it is formed by the combination of KBr and water so it is a mixture.

Learn more:

1. The major contribution of Antoine Lavoisier to chemistry: brainly.com/question/2500879
2. Example of physical change: brainly.com/question/1119909

Answer details:

Grade: High School

Chapter: Elements, compounds, and mixtures

Subject: Chemistry

Keywords: mixture, physical combination, substances, fixed formula, variable, composition, retention, properties, Br2, K, KBr.

Answer:

speaker

Explanation:

speaker runs by the help of electrical energy and the magnetic energy is used and finally it is converted into sound energy

Answer:

the motor in today's standard power drills. the motor in today's standard power saws. the motor in an electric tooth brushes.

Explanation:

More axamples could be that both devices work because of electromagnetic induction, which is when a voltage is induced by a changing magnetic field.