Tag: look, learn and experience

Questions Related to look, learn and experience

The element which is a liquid above $30^oC$ is:

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

  1. Cesium

  2. Lithium

  3. Sodium

  4. Magnesium

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Correct Option: A
Explanation:

The metals which exists as liquids above 30 degree celcius are :-

1)Mercury-(Also in room temperature) 

2)Cesium

3)gallium

Carbon dioxide is associated with:

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

  1. Elements

  2. Mixture

  3. Compound

  4. None of these

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Correct Option: C
Explanation:

Carbon dioxide is a naturally occurring chemical compound composed of 2 oxygen atoms each covalently double bonded to a single carbon atom. It is a gas at standard temperature and pressure and exists in Earth's atmosphere in this state, as a trace gas at a concentration of $0.04 \%$ by volume.

Example of an element is:

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

  1. Water

  2. Sodium hydroxide

  3. Hydrogen

  4. Sugar

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Correct Option: C
Explanation:

A chemical element is a pure chemical substance consisting of a single type of atom distinguished by its atomic number, which is the number of protons in its atomic nucleus. If you change the number of protons an atom has, you change the type of element it is.

Here, hydrogen is an element while water, sodium hydroxide and sugar are compounds made up of more than elements.

Classification of matter helps us to:

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

  1. study things systematically

  2. share information with others

  3. know the properties of all the members of a group if we know about one

  4. All of the above

Show answer
Correct Option: D
Explanation:

Classification of matter helps us to:


(i) Know the properties of all members of a group if we know about one.


(ii) Study things systematically.

(iii) Share information with others.


Option D is correct.

Which among the following is associated with iron sulphide ?

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

  1. Element

  2. Mixture

  3. Compound

  4. None of these

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Correct Option: C
Explanation:

Iron(II) sulfide or ferrous sulfide is a chemical compound with the formula $FeS$. Iron sulfides are often non-stoichiometric. powdered iron sulfide is pyrophoric (ignites spontaneously in air).

The property that we use for classifying things depends on the ___________ of the classification.

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

  1. grouping

  2. purpose

  3. information

  4. system

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Correct Option: B
Explanation:

Things are always classified to make 

(i)easy identification of things.
(ii)Can know all properties of group if we know about one element in the group.
The property that we use  for classifying things depend on the purpose of classification.

Which of the following is not a transition element?

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

  1. Mn

  2. Fe

  3. Cu

  4. K

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Correct Option: D
Explanation:

K belongs to first group. It is a normal metal. Elements of d block are transition metals. Hence K is not a transition metal

Identify the compound from the following.

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

  1. Carbon dioxide

  2. Iron

  3. Hydrogen

  4. Air

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Correct Option: A
Explanation:
A compound is mixture of elements and molecules ,
Iron - element
Hydrogen - element
$CO _2$ - compound
Air - mixture
Oxygen - element

 Option (A) is correct.

Which of the following is not a compound?

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

  1. Sulphur dioxide

  2. Chalk

  3. Lead

  4. Sulphuric acid

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Correct Option: C
Explanation:

Lead $(Pb)$ is not a compound. It is an element present in its pure form so it a single homogeneous identity. Compounds have two or more elements present in the uniform composition in the compound state.


Sulphur dioxide $(SO _2)$ is formed by two elements namely, sulphur and oxygen.

Sulphuric acid $(H _2SO _4)$ is a compound formed by hydrogen, sulphur and oxygen.
The chemical formula for chalk is CaCO3 which is made up of carbon, calcium and oxygen.

Hence, option $C$  is correct.

What is the name given to a pure substance with only one kind of atoms?

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. Mixture

  4. Suspension

Show answer
Correct Option: A
Explanation:

Element is a chemical substance which is composed of same type of atoms or only of single kind e.g., periodic table consist of all elements in its pure form like $Na,\ Mg,\ Cu,\ Pb$ etc.