Scientific investigation: The process in which scientist solve the question by using different systematic approach. It can be initiated in different ways.
Experimental Scientific investigation: The investigation in which scientist answer the question on the basis of experimental results. Experimental investigation includes both dependent and independent variables, and only one variable is tested at a time is possible.
The best example of an experimental scientific investigation is: when we placed a whole apple and apple slice under sun, and noted down how many days it will take to rot in order to compare the break down of apple slice and whole apple.
Thus, option (B) is the correct answer.
Answer:
Reaction 5: Decomposition reaction.
Reaction 6: Single replacement reaction
Reaction 7: Combination reaction.
Reaction 8: Combustion reaction.
Explanation:
<u><em>Reaction 5:</em></u> 2KClO₃ → 2KCl + 3O₂.
- It is a decomposition reaction.
- A decomposition reaction is a type of chemical reaction in which a single compound breaks down into two or more elements or new compounds.
- In this reaction: potassium chlorate decomposes into two single components (potassium chloride and oxygen).
- So, it is a decomposition reaction.
<u><em>Reaction 6:</em></u> Zn + 2HCl → H₂ + ZnCl₂.
- It is a single replacement reaction.
- A single-replacement reaction, a single-displacement reaction, is a reaction by which one (or more) element(s) replaces an/other element(s) in a compound.
- It is most often occur if element is more reactive than the other, thus giving a more stable product.
- In this reaction, zinc metal (more active) displaces the hydrogen to form hydrogen gas and zinc chloride, a salt. Zinc reacts quickly with the acid to form bubbles of hydrogen.
<u><em>Reaction 7:</em></u> N₂O₅ + H₂O → 2HNO₃.
- It is a combination "synthesis" reaction.
- A synthesis reaction has two or more reactants and only one product.
- In this reaction, dinitrogen pentoxide reacts with water to produce nitric acid.
- So, it is considered as a synthetic "combination" reaction.
<u><em>Reaction 8:</em></u> 2C₂H₆ + 7O₂ → 4CO₂ + 6H₂O.
- It is a combustion reaction.
- A combustion reaction is a reaction where hydrocarbon alkane is completely burned in oxygen to produce water and carbon dioxide.
- In this reaction 1.0 mole of ethane is burned to give 4.0 moles of carbon dioxide and 6.0 moles of water.
- So, it is considered as a combustion reaction.
Answer:
Because of less weight kick ball has more acceleration.
Explanation:
Acceleration of kick ball:
5 m/s
Acceleration of soccer ball:
3 m/s
Newton's second law:
According to newton's second law the acceleration of object depends upon two variables.
1) Mass of object
2) Force acting on it
Mathematical expression:
a = f/m
a = acceleration
f = force
m = mass
The force on balls are same thus the acceleration is depend upon the masses of balls.
The soccer ball has more weight that's why its acceleration is less while kick ball is lighter and thus its acceleration will more.
The reaction of a metal with oxygen to form rust is called as redox reaction.
Explanation:
The process during which the surface of metal reacts with the oxygen ions present in air, it has tendency to get oxidized that is formation of an oxide layer on the surface of the metal. Generally, it occurs when metals like iron comes in contact with moisture or water. So the oxygen in moisture reacts with iron giving its electron and getting oxidized and reducing the surface of metal by forming metal oxide. So the complete process of formation of rust is termed as redox reaction. As here both oxidation and reduction is taking place.
