Tag: general introduction: importance and scope of chemistry

Questions Related to general introduction: importance and scope of chemistry

The lightest and the most abundant element in the universe is:

evs look, learn and experience matter: states, classification and properties study of matter general introduction: importance and scope of chemistry

  1. zinc

  2. hydrogen

  3. sodium

  4. mercury

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Correct Option: B
Explanation:

The lightest and the most abundant element in the universe is hydrogen. The percentage of hydrogen in the universe is more than $91$%.


Therefore, hydrogen is the most abundant element in the universe.

Hence, option B is correct.

What is the base of all matter?

evs look, learn and experience matter: states, classification and properties study of matter general introduction: importance and scope of chemistry

  1. Compound

  2. Mixture

  3. Element

  4. None of above

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Correct Option: C
Explanation:

An element consists of only one type atom. All compounds, mixtures etc. consists of element. Hence, element is the basis of all the matter.

Which if the following is used in making smoke bombs ?

evs look, learn and experience matter: states, classification and properties study of matter general introduction: importance and scope of chemistry

  1. Sulphur

  2. Phosphorus

  3. Hydrogen

  4. Carbon

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Correct Option: B
Explanation:

Phosphorus is used in making smoke bombs.

Statement 1 : Iron is an element.


Statement 2 : It cannot be broken into smaller units and retain its physical and chemical properties.

evs look, learn and experience matter: states, classification and properties study of matter general introduction: importance and scope of chemistry

  1. Both Statement 1 and Statement 2 are correct and Statement 2 is the correct explanation of Statement 1

  2. Both Statement 1 and Statement 2 are correct and Statement 2 is not the correct explanation of Statement 1

  3. Statement 1 is correct but Statement 2 is not correct

  4. Statement 1 is not correct but Statement 2 is correct

  5. Both the Statement 1 and Statement 2 are not correct

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Correct Option: A
Explanation:

Iron is an element found in nature as the third most abundant element in the earth's crust.


Element is a pure substance with a single element and cannot be further divided into its constituent elements.

Hence the correct option is A.

Snow and ice can from compound.

evs look, learn and experience matter: states, classification and properties study of matter general introduction: importance and scope of chemistry

  1. True

  2. False

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Correct Option: B
Explanation:

Snow and ice cannot form compounds because they are same water molecules in solid state grouped together by hydrogen bonds. Snow and ice cannot form compound because they both are similar.

True or False.


Baking soda is a compound.

evs look, learn and experience matter: states, classification and properties study of matter general introduction: importance and scope of chemistry

  1. True

  2. False

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Correct Option: A
Explanation:

Baking soda is a compound because it's composed of molecules that are all identical. It has the chemical formula $NaHCO _3$ and the chemical name sodium hydrogen carbonate. Pure baking soda is a compound, NaHCO3. But in most cases the white powder will be a mixture between $NaHCO _3$ and $Na _2CO _3$, which resulted after the decomposition of $NaHCO _3$:

$2NaHCO _3 \rightarrow  Na _2CO _3 + CO _2 + H _2O$

In an experiment oxygen was added to hydrogen and heated. On burning a substance containing both oxygen and hydrogen water was formed. What is this substance?

evs look, learn and experience matter: states, classification and properties study of matter general introduction: importance and scope of chemistry

  1. Element

  2. Compound

  3. Solution

  4. Mixture

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Correct Option: B
Explanation:

Oxygen and hydrogen are two elements and when they react they must generate another compound. Their product is not a mixture and  their result is a different compound with different properties.

Matter can be hard or soft

evs look, learn and experience matter: states, classification and properties study of matter general introduction: importance and scope of chemistry

  1. True

  2. False

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Correct Option: A
Explanation:

Matter is any substance that has mass and takes up space; this includes atoms and anything made up of these, hence it can be hard or soft.

The first and last elements of the longest period are ___________.

evs look, learn and experience matter: states, classification and properties study of matter general introduction: importance and scope of chemistry

  1. francium and Uuo

  2. caesium and radon

  3. francium and radon

  4. caesium and Uuo

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Correct Option: B
Explanation:

Longest period is 6th period. It contains 32 elements. It starts with Caesium. The last element is Radon. 

7th period is not the longest as it contains less than 32 elements.

A, B, C are three elements with atomic numbers, Z-1, Z, and Z+1 respectively. B is an inert gas.
Identify the elements having same valence shell.
evs look, learn and experience matter: states, classification and properties study of matter general introduction: importance and scope of chemistry

  1. A, B

  2. B, C

  3. A, C

  4. A, B, C

Show answer
Correct Option: A
Explanation:

Three elements A,B and C. B is a noble gas, A has atomic number 1 less than B and C has 1 more than B. Hence number of valence shell is same in A and B because on adding one electron to Noble gas that is 18 group next electron will occupy, alkali metals group in a next period hence increases in shell number.