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.
A.) half - life of a radioactive substance is defined as the time during which concentration of the substance becomes half the initial value.
Answer:
<em>What is atmospheric pressure? -------> Atmospheric pressure is a force in an area pushed against a surface by the weight of the atmosphere of Earth, a layer of air.</em>
<em>Why does the atmosphere exert pressure? -------> Because gas particles in the air—like particles of all fluids—are constantly moving and bumping into things, so they exert pressure. </em>
<em>What is the value of atmospheric pressure at sea level, in newtons per square centimeter? -------> Atmospheric pressure at sea level is about 10 N/cm2 or 100 kPa or about 10 m of water or about 760 mm of mercury, but varies with the weather, and of course altitude.</em>
<em>I hope this helps and have a great day!</em>
Explanation:
The statement the chemical makeup of the universe has changed dramatically provides evidence that supports the Big Bang Theory (Option D).
<h3>What is the Big Bang Theory?</h3>
The Big Bang Theory is a widely accepted theory in physics that states all the universe began with a huge explosion and form then matters expanded in space at the same time that it is cooling.
Therefore, with this data, we can see that the Big Bang Theory states that the chemical composition of the universe associated with hydrogen and helium modified since this explosion.
Learn more about the Big Bang Theory here:
brainly.com/question/1973038
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