Question 4 :
Solder is an alloy of lead and tin. It has a :
Question 8 :
State true or false: The galvanised article is protected against rusting even if the zinc coating is broken.
Question 10 :
State true or false: Alloying a very effective method of improving the properties of a metal.
Question 12 :
Name two metals which will not displace hydrogen from dilute acids.
Question 13 : <img style='object-fit:contain' src='https://teachmint.storage.googleapis.com/question_assets/cbse_ncert/61b19d4c273b230584979bd9.JPG' />
From the above image, answer the following: Pratyush took sulphur powder on a spatula and heated it. He collected the gas evolved by inverting a test tube over it, as shown in figure above. What will be the action of gas on dry litmus paper?
Question 14 :
Food cans are coated with tin and not with zinc because :
Question 16 :
What type of oxides are formed when non-metals combine with oxygen?
Question 17 :
An element reacts with oxygen to give a compound with a high melting point. This compound is also soluble in water. The element is likely to be :
Question 20 :
Which of the following methods is suitable for preventing an iron frying pan from rusting?
Question 21 : <img style='object-fit:contain' src='https://teachmint.storage.googleapis.com/question_assets/cbse_ncert/61b19d4d273b230584979bda.JPG' />
From the above image, answer the following: Pratyush took sulphur powder on a spatula and heated it. He collected the gas evolved by inverting a test tube over it, as shown in figure above. What will be the action of gas on moist litmus paper?
Question 27 :
Select the metal which can be easily cut with a knife.
Question 29 :
Which gas is produced when dilute hydrochloric acid is added to a reactive metal?
Question 33 :
Which gas is produced when dilute hydrochloric acid is added to a reactive metal?
Question 34 :
Write chemical raction when zinc is added to a solution of iron(II) sulphate.
Question 36 : <img style='object-fit:contain' src='https://teachmint.storage.googleapis.com/question_assets/cbse_ncert/61b19d4f273b230584979bdc.JPG' />
From the above image, answer the following: Samples of four metals A, B, C, D were taken and added to the solutions one by one. Results obtained have been tabulated. Which is the most reactive metal?
Question 42 :
Two metals which are found in nature in the free state are ___ and ____.
Question 45 :
State true or false: Metals lying above hydrogen in activity series can displace hydrogen from dilute acids.
Question 54 :
Which of the following are the environmental consequences of the increasing demand in energy?
Question 55 :
Waste from a nuclear power plant can be easily disposed off. TRUE or FALSE ?
Question 56 :
Which of the following is not an example of bio-mass energy source?
Question 58 :
We are encouraged to plant more trees so as to ensure clean environment and also provide bio-mass fuel. TRUE or FALSE ?
Question 59 :
Most of the sources of energy we use to represent stored solar energy. Which of the following is not ultimately derived from the solar energy?
Question 63 :
Sun can be taken as an inexhaustible source of energy. TRUE or FALSE ?
Question 64 :
Energy from various sources is considered to have been derived from the sun. Do you agree?
Question 65 :
Which part of the solar cooker is responsible for green house effect?
Question 67 :
Most of the sources of energy we use represent stored solar energy. Which of the following is not ultimately derived from the sun's energy?
Question 68 :
Which one of the following forms of energy leads to least environmental pollution in the process of its harnessing and utilisation?
Question 73 :
Hydrogen has been used as a rocket fuel. Would you consider it a cleaner fuel than CNG?
Question 74 :
Which of the following is not an example of bio-mass energy resource?
Question 75 :
There is infinite storage of fossil fuel inside the earth. TRUE or FALSE ?
Question 77 :
Gobar-gas is produced when crops, vegetable wastes etc., decompose in the absence of oxygen. TRUE or FALSE ?
Question 79 :
A solar water heater cannot be used to get a hot water on:
Question 80 :
Which of the following would be the steps you suggest to reduce energy consumption?
Question 83 :
Which of the following is/are the advantages of a solar cooker?
Question 85 :
What is the role of a plane mirror in a solar cooker?
Question 86 :
What is the role of a glass sheet in a solar cooker?
Question 88 :
Which is the process used to harness nuclear energy these days?
Question 90 :
Asolar water heater cannot be used to get hot water on:
Question 91 :
Bio-mass is a renewable source of energy. TRUE or FALSE ?
Question 92 :
Which is the major direct environmental consequences of using fossil fuels?
Question 94 :
Hydro and wind energy plants are non polluting sources of energy. TRUE or FALSE ?
Question 95 :
In a hydroelectric power plant more electrical power can be generated if water falls from a greater height because
Question 99 :
The main ingredient of bio-gas is ethane and it gives a lot of smoke and also produces a lot of residual ash. TRUE or FALSE ?
Question 100 :
What kind of mirror-concave, convex or plane would be best suited for use in a solar cooker?
Question 103 :
Gather information about the chromosome numbers of five animals and five plants. Correlate the number with the size of organism and answer the following questions: More the number of chromosomes/cells greater is the DNA content.
Question 107 :
State whether the statement is TRUE or FALSE : Sexual reproduction in flowering plant,Offspring formed are clones.
Question 108 :
What changes are observed in the uterus subsequent to implantation of young embryo?
Question 109 :
In a flower, the parts that produce male and female gametes (germ cells) are
Question 110 :
State whether the statement is TRUE or FALSE : Sexual reproduction in flowering plants requires two types of gametes.
Question 111 :
The correct sequence of organs in the male reproductive system for transport of sperms is
Question 112 :
State whether the statement is TRUE or FALSE : Flowers are always bisexual.
Question 113 :
<image = 'https://s3.ap-south-1.amazonaws.com/homeworkcontent/christina%2F3.PNG'>
In the above figure, which part mention the function Site of implantation.
Question 114 :
State whether the statement is TRUE or FALSE : Flowers are produced in all groups of plants.
Question 116 :
State whether the statement is TRUE or FALSE : Amoeba is reproduced by the asexual method.
Question 117 :
In human males, the testes lie in the scrotum, because it helps in the
Question 118 :
State whether the statement is TRUE or FALSE : Unisexual flowers possess both stamen and pistil.
Question 120 :
State whether the statement is TRUE or FALSE : Dog is reproduced by the asexual method.
Question 121 :
What changes are observed in the uterus if fertilisation does not occur?
Question 122 :
State whether the statement is TRUE or FALSE : Offspring formed by asexual method of reproduction have greater similarity among themselves because asexual reproduction involves only one parent.
Question 123 :
Gather information about the chromosome numbers of five animals and five plants. Correlate the number with the size of organism and answer the following questions: Can organism with fewer chromosomes reproduce more easily than organisms with more number of chromosomes?
Question 124 :
Factors responsible for the rapid spread of bread mould on slices of bread are presence of tubular branched hyphae. Is it true or false?
Question 125 :
Why does bread mould grow profusely on a moist slice of bread rather than on a dry slice of bread?
Question 126 :
Gather information about the chromosome numbers of five animals and five plants. Correlate the number with the size of organism and answer the following questions: Do larger organisms have more number of chromosomes/cells?
Question 127 :
State whether the statement is TRUE or FALSE : Unisexual flowers possess either stamen or pistil.
Question 128 :
<image = 'https://s3.ap-south-1.amazonaws.com/homeworkcontent/christina%2F3.PNG'>
In the above figure, which part mention the function Production of egg
Question 129 :
In Rhizopus, tubular thread-like structures bearing sporangia at their tips are called
Question 132 :
Can you consider cell division as a type of reproduction in unicellular organism?
Question 134 :
<image = 'https://s3.ap-south-1.amazonaws.com/homeworkcontent/christina%2F3.PNG'>
In the above figure, which part mention the function Site of fertilisation.
Question 135 :
State whether the statement is TRUE or FALSE : Flowers are the sexual reproductive organs.
Question 136 :
State whether the statement is TRUE or FALSE : Offspring formed by asexual method of reproduction have greater similarity among themselves because asexual reproduction occurs after sexual reproduction.
Question 138 :
State whether the statement is TRUE or FALSE : Unisexual flowers exhibit cross pollination.
Question 139 :
In human females, an event that reflects onset of reproductive phase is
Question 140 :
State whether the statement is TRUE or FALSE : After fertilisation Flowers give rise to fruits.
Question 141 :
Whether secretion of estrogen is the function of testes at puberty?
Question 142 :
State whether the statement is TRUE or FALSE : Banana is reproduced by the asexual method.
Question 144 :
Is the chromosome number of zygote, embryonal cells and adult of a particular organism always constant?
Question 145 :
Why cannot fertilisation take place in flowers if pollination does not occur?
Question 146 :
State whether the statement is TRUE or FALSE : Unisexual flowers possessing only stamens cannot produce fruits.
Question 148 :
State whether the statement is TRUE or FALSE : Offspring formed by asexual method of reproduction have greater similarity among themselves because asexual reproduction does not involve gametes.
Question 149 :
The ability of a cell to divide into several cells during reproduction in Plasmodium is called
Question 150 :
State whether the statement is TRUE or FALSE : Offspring formed by asexual method of reproduction have greater similarity among themselves because asexual reproduction occurs before sexual reproduction.
Question 151 :
An aluminium strip is kept immersed in freshly prepared ferrous sulphate solution taken in a test tube, the change observed is that
Question 153 :
Which one of the following metals is the most reactive and stored in kerosene?
Question 154 :
Which of the following methods is suitable for preventing an iron frying pan from rusting?
Question 156 :
The earthly or undesired materials associated with an ore are called
Question 157 :
Which among the following alloys contain non-metal as one of its constituents?
Question 158 :
An element reacts with oxygen and give slaked lime. The element is
