ANSWER 1
(C) FLAMMABILITY
Flammability is a chemical property and is not a physical property. It can be only observed when the substance changes from one form to another. For example, a paper is a flammable substance and after being burned it changes itself into ashes and doesn't remain a paper anymore.
ANSWER 2
(B) SOLID
Solid holds a fix volume and shape. The particles of a solid are held into their place and cannot be compressed thus forming a rigid structure. There is very little space between the particles hence, they cannot move.
ANSWER 3
(D) ALL OF THE ABOVE ARE A EVIDENCE OF CHEMICAL REACTION
There are 5 simple ways to depict if any chemical reaction has occurred or not. It includes color change, the formation of ppt, effervescence, light emission and temperature changes.
COLOR CHANGES: A change in color can clearly tell you that a chemical reaction has occurred. for example, a brown copper liberty statue has turned green due to a series of chemical reactions.
FORMATION OF PPT: The formation of precipitate shows that a chemical reaction has been done. It is the formation of insoluble solid from the liquid solution.
BUBBLES OF GAS: Some of the reactions produce gas as their final product. For example in the electrolysis of water one can observe clear bubbles arising from the electrodes.
ANSWER 4
FALSE
In a homogenous mixture, the components composition which makes up the mixture remains unchanged. In a vegetable soup and chocolate chip cookies, the amount of ingredients used does not remain the same till the end.
ANSWER 5
(D) ALUMUNIUM
A pure substance only contains one element. An aluminum is only made up of one substance while the other three things are a mixture of different substances. Like air is a mixture of hydrogen, oxygen and other gases, salt water is a mixture of sodium and water and granite is made up of different compounds. All of these three are heterogeneous mixtures.
ANSWER 6
(A) Potassium iodide
To name this organic chemical organic compound one has to make use of IUPAC nomenclature. The compound KI contains an element from the halide group that is group 7. According to the priority table, iodine should become the parent name.
ANSWER 7
FALSE
According to the law of conservation of mass, in an isolated system, the mass can never be created nor destroyed by chemical or physical means. In simple words, it means that after a chemical reaction the total mass of the reactants will be the same as of the product.
ANSWER 8
(A) Single replacement
In the above-mentioned reaction that is;
Na + KCl ⇒ K + NaCl
Single replacement is observed as sodium takes the place of potassium. Sodium is much reactive than potassium thus quickly removes potassium from the compound and combines with chlorine to form sodium chloride.
ANSWER 9
(D) ADDING MORE POWDERED DRINK MIX
All of the above answers are correct. As quick stirring and breaking the solute into smaller pieces will increase the surface area of the substance and heating the mixture increases the kinetic energy of the particles, thus making them vibrate faster. Hence all of these things make the powdered drink mix to be dissolved easily.
ANSWER 10
(D) 0.77g/cm3
The formula for density was proposed by the mathematician Archimedes. It is dividing the mass of a substance with the volume of the substance. By dividing 5.854g of the material with 7.57cm3 of the substance we will get 0.77g/cm3.