📄 GuideTwo friends are standing along a steel fence at a distance of 340 m from each other. Class 9
Two friends are standing along a steel fence at a distance of 340 m from each other. Class 9Question
📄 GuideFor the sound wave represented by the graph shown in Fig., what is half of its wavelength? Class 9
For the sound wave represented by the graph shown in Fig., what is half of its wavelength? Class 9Qu
📄 GuideConduct Activity 1 once again with a thick rubber band and then with a thin rubber band. Class 9
Conduct Activity 1 once again with a thick rubber band and then with a thin rubber band. Class 9Ques
📄 GuideWhen sound travels from a tuning fork to your ear, which of the following actually reaches your ear? Class 9
When sound travels from a tuning fork to your ear, which of the following actually reaches your ear?
📄 GuideWe cannot hear the sound of a bell ringing in a closed jar after most of the air is pumped out. Class 9
We cannot hear the sound of a bell ringing in a closed jar after most of the air is pumped out. Clas
📄 GuideExplore various ways of producing sound. Class 9
Explore various ways of producing sound. Class 9Pause and Ponder (Page 186)Question 1. Explore vario
📄 GuideTwo astronauts are repairing the arm of a space station together during a spacewalk. Class 9
Two astronauts are repairing the arm of a space station together during a spacewalk. Class 9Think It
📄 GuideYou clap in hall and hear an echo after 0.5 s. If speed of sound in air is 340 m/s. Class 9
You clap in hall and hear an echo after 0.5 s. If speed of sound in air is 340 m/s. Class 9Question
📄 GuideActivity 10.8 Let us experiment to study how frequency affects hearing and determine the range. Class 9
Activity 10.8 Let us experiment to study how frequency affects hearing and determine the range. Clas
📄 GuideFrom graph of sound wave propagating in steel, find its wavelength. Class 9
From graph of sound wave propagating in steel, find its wavelength. Class 9Question 1. From graph of
📄 GuideActivity 10.7 Let us experiment to study how the frequency of sound changes. Class 9
Activity 10.7 Let us experiment to study how the frequency of sound changes. Class 9Activity 10.7 Le
📄 GuideActivity 10.6 Let us experiment to show that sound is a form of energy. Class 9
Activity 10.6 Let us experiment to show that sound is a form of energy. Class 9Activity 10.6 Let us
📄 GuideActivity 10.5 Let us observe to study how waves (disturbances) travel through a medium. Class 9
Activity 10.5 Let us observe to study how waves (disturbances) travel through a medium. Class 9Activ
📄 GuideActivity 10.4 Let us investigate to show that sound can travel through liquids and needs a medium. Class 9
Activity 10.4 Let us investigate to show that sound can travel through liquids and needs a medium. C
📄 GuideActivity 10.3 Let us investigate to show that sound can travel through solids. Class 9
Activity 10.3 Let us investigate to show that sound can travel through solids. Class 9Activity 10.3
📄 GuideActivity 10.2 Let us explore to show that sound is produced due to vibrations using a tuning fork. Class 9
Activity 10.2 Let us explore to show that sound is produced due to vibrations using a tuning fork. C
📄 GuideActivity 10.1 Let us explore to show that sound is produced due to vibrations of objects. Class 9
Activity 10.1 Let us explore to show that sound is produced due to vibrations of objects. Class 9Act
📄 GuideThe species 27Al, 80Br- and 201Hg2+ have 13, 35 and 80 protons, respectively. Class 9
The species 27Al, 80Br- and 201Hg2+ have 13, 35 and 80 protons, respectively. Class 9Question 1. The
📄 GuideCopper sulfate conducts electricity in the molten state but not in the solid state. Class 9
Copper sulfate conducts electricity in the molten state but not in the solid state. Class 9Question
📄 GuideTwo elements, A and B, have the following configurations. Class 9
Two elements, A and B, have the following configurations. Class 9Question 1. Two elements, A and B,
📄 Guide5.3 g of sodium carbonate and 6.0 g of acetic acid react to produce 2.2 g of carbon dioxide. Class 9
5.3 g of sodium carbonate and 6.0 g of acetic acid react to produce 2.2 g of carbon dioxide. Class 9
📄 GuideComplete the table by writing the formulae of the compounds formed by the cations. Class 9
Complete the table by writing the formulae of the compounds formed by the cations. Class 9Question 1
📄 GuideWrite the formulae for the compounds formed by the reaction of. Class 9
Write the formulae for the compounds formed by the reaction of. Class 9Question 1. Write the formula
📄 GuideDetermine the formula unit mass of the following substances. Class 9
Determine the formula unit mass of the following substances. Class 9Question 1. Determine the formul
📄 GuideWrite the formulae of the compounds formed from the following pairs of ions. Class 9
Write the formulae of the compounds formed from the following pairs of ions. Class 9Question 1. Writ
📄 GuideElements are made up of molecules and compounds are made up of atoms. Class 9
Elements are made up of molecules and compounds are made up of atoms. Class 9Question 1. Choose the
📄 GuideAn element X has six electrons in its outer shell and forms a diatomic molecule. Class 9
An element X has six electrons in its outer shell and forms a diatomic molecule. Class 9Question 1.
📄 GuideA particular element (A) has one electron in its third shell. There is another element (B). Class 9
A particular element (A) has one electron in its third shell. There is another element (B). Class 9R
📄 GuideFind the formula unit mass of magnesium hydroxide, Mg(OH)2. Class 9
Find the formula unit mass of magnesium hydroxide, Mg(OH)2. Class 9Question 1. Find the formula unit
📄 GuideFind the molecular mass of methane (CH4). Class 9
Find the molecular mass of methane (CH4). Class 9Question 1. Find the molecular mass of methane (CH4
📄 GuideMetal M, with two electrons in its valence shell (M shell), reacts with oxygen. Class 9
Metal M, with two electrons in its valence shell (M shell), reacts with oxygen. Class 9Question 1. M
📄 GuideWhat type of chemical bond is present in a solid compound that does not conduct electricity. Class 9
What type of chemical bond is present in a solid compound that does not conduct electricity. Class 9
📄 GuideWrite the formula for the following. Sodium hydrogencarbonate. Class 9
Write the formula for the following. Sodium hydrogencarbonate. Class 9Question 1. Write the formula
📄 GuideIllustrate how sodium sulfide (Na2S) is formed. Class 9
Illustrate how sodium sulfide (Na2S) is formed. Class 9Question 1. Illustrate how sodium sulfide (Na
📄 GuideShow the formation of cations of potassium (K) and calcium (Ca) atoms, and the formation. Class 9
Show the formation of cations of potassium (K) and calcium (Ca) atoms, and the formation. Class 9Que
📄 GuideWhat kind of ion will oxygen (O) form? Class 9
What kind of ion will oxygen (O) form? Class 9(Page 174)Question 1. What kind of ion will oxygen (O)
📄 GuideNeon (atomic number 10) neither transfers nor shares its valence electrons. Explain. Class 9
Neon (atomic number 10) neither transfers nor shares its valence electrons. Explain. Class 9Question
📄 GuideShow the formation of the following molecules. Carbon dioxide, Hydrogen sulfide. Class 9
Show the formation of the following molecules. Carbon dioxide, Hydrogen sulfide. Class 9(Page 171)Qu
📄 GuideNitrogen has five valence electrons. Draw the structure of the nitrogen molecule (N2). Class 9
Nitrogen has five valence electrons. Draw the structure of the nitrogen molecule (N2). Class 9(Page
📄 Guide2 g of hydrogen combines with 16 g of oxygen to form 18 g of water. Class 9
2 g of hydrogen combines with 16 g of oxygen to form 18 g of water. Class 9(Page 168)Question 1. Ass
📄 GuideThe Law of Definite Proportions holds true for compounds but not for mixtures. Class 9
The Law of Definite Proportions holds true for compounds but not for mixtures. Class 9Question 1. Th
📄 GuideA compound consists of 40% sulfur and 60% oxygen by mass. In a sample of the same compound. Class 9
A compound consists of 40% sulfur and 60% oxygen by mass. In a sample of the same compound. Class 9(
📄 GuideA student burns 10 g of ethanol in an open beaker. After the reaction. Class 9
A student burns 10 g of ethanol in an open beaker. After the reaction. Class 9Pause and Ponder (Page
📄 GuideWater can be obtained from various sources. Are all these samples of water chemically identical? Class 9
Water can be obtained from various sources. Are all these samples of water chemically identical? Cla
📄 GuideWater can be obtained from various sources. Are all these samples of water chemically identical? Class 9
Water can be obtained from various sources. Are all these samples of water chemically identical? Cla
📄 GuideCalculate the formula unit mass of magnesium hydroxide, Mg(OH)2. Class 9
Calculate the formula unit mass of magnesium hydroxide, Mg(OH)2. Class 9Question 1.Calculate the for
📄 GuideCalculate the formula unit mass of sodium oxide (Na2O). Class 9
Calculate the formula unit mass of sodium oxide (Na2O). Class 9Question 1.Calculate the formula unit
📄 GuideActivity 9.5 To check the solubility of some compounds in water and organic solvents. Class 9
Activity 9.5 To check the solubility of some compounds in water and organic solvents. Class 9Activit
📄 GuideCalculate the molecular mass of nitric acid (HNO3). Class 9
Calculate the molecular mass of nitric acid (HNO3). Class 9Question 1. Calculate the molecular mass
📄 GuideCalculate the molecular mass of water (HaO). Class 9
Calculate the molecular mass of water (HaO). Class 9Question 1.Calculate the molecular mass of water