Important Points to remember

• Scientific Study: The systematic ways to learn facts is called scientific study

• Scientific Method: The steps of scientific study is called scientific method. It includes observation , questioning, hypothesis, experiment, analysis, result and communication. 

• Scientific process Skill : The basic skills required for scientific study is called science process skill. It includes observation, questioning, classification, prediction, interpretation, measurement, concluding, communication etc. 

• Biology:  The branch of science which study about living things is called biology.

• Chemistry: The branch of science which study about the properties of matter on the basis of atoms and molecules is called chemistry.

• Physics: The branch of science which study about natural phenomena on the basis of force, motion and energy is called physics.

• Biologist:  An expert of biology is called  a biologist.

• Chemist:  An  expert of chemistry is called  a chemist.

• Physicist:  An expert of physics is called a physicist. 

• Scientific Notation : The method of representing very large or very small numbers as a factor of power of ten is called scientific notation.  for example small number 0.0000042 is represent as 4.2✕10-6 

• Metric Prefix: The prefix used to represent very large or very small quantities in SI units is called metric prefix. For example; 20000 m can be written as 20km, where k (kilo) is a prefix .

• Least Count: The smallest value that can be measured by an instrument is called the least count. For example least count of scale is 0.1 cm, least count of protractor is 1 degree. 

Exercise

1. Tick the correct answer.

i) Which branch does the veterinary profession belong to ? - Biology

ii) Which field of science does Johann Gregor Mendel represent ? - Biology

iii) Which one is least count when measured from scale ? - milimeter

iv) How is 0.000024 expressed in scientific notation. - 2.4✕10-5 

v) What is the value of giga prefix ? - 109 

2. Answer the following questions. 

a) How is scientific study is done ? Explain. 

👉 Scientific study is done various steps. The first step for scientific study is observation of some events or problems. Hypotheses is built in the second step and data are collected after experiment in the third step. In the fourth step, the result an conclusion is made from the analysis of collected data. The hypotheses is tested either right or  wrong at the fifth step. If the hypotheses is verified, then the  report is prepared and communicated to others. If hypotheses is not justified, the hypotheses can be modified and all the above steps are repeated. 

b) Enlist the field of science.

👉 The fields of science are as follows;

      i) Physics ii) Biology

     iii) Chemistry iv) Geology

     v) Astronomy

c) Describe the interrelationship among the fields of science with examples.

👉 Physics is the foundation, studying the fundamental laws that govern the universe, from the smallest subatomic particles to the largest galaxies. Chemistry builds on these laws to understand how matter interacts at the atomic and molecular level, forming the building blocks of life. Finally, biology applies the principles of physics and chemistry to understand living organisms, from their cells and tissues to their ecosystems.

For example: every living thing needs energy to move and grow. In biology, we learn about how animals get energy from food. But how does that food turn into energy ? That's chemistry. And physics helps us to understand how this energy is used to move our muscles.

d) What is the value of experiment in scientific study ? Explain with examples.

👉 Experiments are very important in scientific study because they allow researchers to test hypotheses, validate theories and establish relationships between variables.

For example; Let us suppose a group of researchers want to investigate the effectiveness of the coronavirus vaccine. The sample vaccine developed is  first injected to the selected animals. For a specific period of time the animal's condition is monitored. They find that the vaccine is working well in those animals. After that it is applied to human beings. 

Without the experiment on animals the researchers would not have been able to test the effectiveness of the vaccine. 

e) Enlist the safety measures while conducting experimental work.

👉 The following are the safety measures while conducting experimental work.

      i) Experiment is done only in the presence of teacher.

      ii) Safety instruments like lab coat, mask, glasses, gloves are used while working in lab.

      iii) Chemical is not tested or touched.

      iv) The door or window must  be opened.

      v) The hand should be washed with soap after finishing the experiment. 

f) Define scientific notation.

👉 The method of representing very large or very small numbers as a factor of power of ten is called scientific notation.

g) Why is metric prefix is important ? Describe with examples.

👉 The metric prefix is important because it makes very large or very small numbers easier and more convenient. For example, 60000 m can be written as 60 km and 0.000001 m can be written as 1μm. 

h) Explain in brief about least count in measurement.

👉 The smallest value that can be measured by an instrument is called the least count. For example least count of scale is 0.1 cm, least count of protractor is 1 degree. The instrument having smaller least count  gets more accurate reading. 

i) Express the given numbers in scientific notation. 

    i) 123000 = 1.23✕106 

    ii) 0.00042 = 4.2✕10–4 

    iii) 0.00000001 = 1✕10-8 

    iv) 300000000 = 3✕108