Test: Basic Units Of Matter


10 Questions MCQ Test Science Class 9 | Test: Basic Units Of Matter


Description
This mock test of Test: Basic Units Of Matter for Class 9 helps you for every Class 9 entrance exam. This contains 10 Multiple Choice Questions for Class 9 Test: Basic Units Of Matter (mcq) to study with solutions a complete question bank. The solved questions answers in this Test: Basic Units Of Matter quiz give you a good mix of easy questions and tough questions. Class 9 students definitely take this Test: Basic Units Of Matter exercise for a better result in the exam. You can find other Test: Basic Units Of Matter extra questions, long questions & short questions for Class 9 on EduRev as well by searching above.
QUESTION: 1

What are the building blocks of matter?

Solution:

The most fundamental building block of matter was a particle called the atom. Now we know that the atom is made of many smaller pieces, known as subatomic particles. Every atom contains a central core called the nucleus, made of particles called protons and neutrons.

QUESTION: 2

How do atoms usually exist in nature?

Solution:

Atoms usually exist in two ways (1) in the form of molecules (2) in the form of ions 

QUESTION: 3

Which atom is the smallest atom of all?

Solution:

The atom with the smallest mass is the hydrogen atom; its mass is about 10-27 kg. 

QUESTION: 4

Which of the following can be used to see atoms?

Solution:

A scanning tunneling microscope (STM) is an instrument for imaging surfaces at the atomic level. Its development in 1981 earned its inventors, Gerd Binnig and Heinrich Rohrer (at IBM Zrich), the Nobel Prize in Physics in 1986. For an STM, good resolution is considered to be 0.1 nm lateral resolution and 0.01 nm (10 pm) depth resolution.With this resolution, individual atoms within materials are routinely imaged and manipulated. The STM can be used not only in ultra-high vacuum but also in air, water, and various other liquid or gas ambients, and at temperatures ranging from near zero kelvin to over 1000 DEGC.

QUESTION: 5

The number of atoms present in one molecule of an element is called as:

Solution:

Atomicity is the total number of atoms present in one molecule of an element or a compound. For example: one molecule of hydrogen (H2) contains two atoms of hydrogen. Therefore, atomicity of hydrogen is 2. Simialrly, 1 molecule of O3 contains 3 atoms. Therefore, its atomicity  is 3. molecule of Argon exist as Ar and hence its a monoatomic compound.

QUESTION: 6

Study of internal structure of Earth is known as

Solution:

A geologist is a person who studies the earth. Geologists study the structure of the Earth, and they have found that it is made up of four main parts. The earth has a solid inner core, a liquid outer core, a mantle, and a crust.hence, option (D) is correct.

QUESTION: 7

Cl2 stands for:

Solution:
QUESTION: 8

Which constituent of air is monoatomic?

Solution:

Argon is a Noble gas. Noble gases are not very reactive since they have a very stable electron configuration. It is only about 1% of the air in the atmosphere but it is more abundant than any other element on the Periodic Table behind Nitrogen and Oxygen.

QUESTION: 9

Molecules can exist in free state because:

Solution:

A combination of atoms is called a molecule. We know that atoms of most of the elements are very reactive and cannot exist in the free state (as single atoms). This is not so with molecules. Molecules can exist in free state because they are very stable.

QUESTION: 10

Which is the smallest particle of an element that can take part in a chemical reaction?

Solution:

An atom can be defined as the smallest particle of an element, which can take part in chemical change or reaction and still retain the identity of the element. Notice that the atom is not the smallest particle of an element, as there are electrons, protons and neutrons which are smaller, but, it is the smallest which can be involved in chemical change and still retain the chemical properties of the element.

Related tests