Answer: B) combustion reaction.
Explanation:
A) acid-base reaction: When an acid reacts with a base, to form metal salt and water, this type of reaction is Acid Base reaction.
Example: 
B) combustion reaction: When a hydrocarbon reacts with oxygen to produce carbon dioxide and water, this type of reaction is combustion reaction.

C) precipitation reaction: a reaction in which aqueous solution of two compounds on mixing react to form an insoluble compound which separate out as a solid are called precipitation reactions.

D) gas evolution reaction: a reaction in which one of the product is formed as a gas.

Answer:
.Periodic trends are specific patterns in the properties of chemical elements that are revealed in the periodic table of elements. Major periodic trends include electronegativity, ionization energy, electron affinity, atomic radii, ionic radius, metallic character, and chemical reactivity.
To find the mass of glucose, you must multiply the atomic weight of each of the elements in the molecule by the subscripts in the formula:



Then you add all of them together:

Therefore, the molar weight of glucose is 180.15 grams.
<u>Answer:</u> The correct answer is Option 2.
<u>Explanation:</u>
Centripetal force is defined as the force that acts on a body moving in a circular path and is directed towards the center around which the body is moving.
Mathematically,

Where,
= centripetal force
m = mass of the object
v = tangential velocity
r = radius of the path
From the above relation, X corresponds to the radius and Y corresponds to the tangential velocity.
Hence, the correct answer is option C.