<u>Answer:</u> The force that must be applied is 15 N.
<u>Explanation:</u>
Force exerted on the object is defined as the product of mass of the object and the acceleration of the object.
Mathematically,

where,
F = force exerted = ?
m = mass of the object = 3 kg
a = acceleration of the object = 
Putting values in above equation, we get:

Hence, the force that must be applied is 15 N.
When methane is burned with oxygen, the products are carbon dioxide and water. If you produce 9 grams of water and 11 grams of carbon dioxide from 16 grams of oxygen, how many grams of methane were needed for the reaction? First you need to write a balanced chemical equation.
In a flame photometric analysis, salt solution is first vaporized using the heat of flame, followed by this electrons from valance shell gets excited from ground state to excited state. Followed by this de-excitation of electron bring backs electrons to ground state. This process is accompanied by emission of photon. The photon emitted is characteristic of an element, and number of photons emitted can be used for quantitative analysis.
<span>Following are the investigative question that you can answer by doing this experiment.
</span>1) What information can be obtained from the colour of flame?
2) <span>State the relationship between wavelength, frequency, and energy?
</span><span>3) Can you identify the metal present in unknown sample provided?
4) How will you identify amount of metal present in sample solution?
5) </span><span>Why do different chemicals emit light of different colour?</span><span>
</span>
D = 0.2 g / ml = 0.2 g / cm³
For example, density of steel is 7.85 g / cm³.
Density of pure water is 1.0 g/cm³. An object which has a density < 1.0 g/cm³ will float in water.
Answer: Material that has a density of 0.2 g/ml ( 0.2 g/cm³ ) is good for making couch cushions.
<span>Answer:
Iron triad are used in the process to create steel and other metal mixtures.
Coinage Metals are used for much more than just coins, and many other elements besides these are made into coins.</span>