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Mohd Anas Khan
Subject: Science
, asked on 6/1/18
Ques a. Define avagadro number. b. Show that 100g of water and 100g of carbon dioxide are not equal in number of moles. Molecular mass of water and carbon dioxide are 18 u and 44 u respectively.
Answer
1
Harsh Sethi
Subject: Science
, asked on 6/1/18
Q. (A) An element X has an atomic number 12 an atomic mass no. 26. Draw a diagram showing the distribution of electrons in the orbits and the nuclear composition of the neutral atom of the element. What is the valency of the element and why?
(B) If this element X combines with another element Y whose electronic configuration is 2,8,7. what will be the formula of the compound thus formed? State how you arrived at this formula.
Answer
5
Swayam Gupta
Subject: Science
, asked on 6/1/18
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Answer
2
Swayam Gupta
Subject: Science
, asked on 5/1/18
Draw the atomic structure of an atom with same number of (1) Sub-atomic particles (2) electrons in L and M shell.
Answer
1
Swayam Gupta
Subject: Science
, asked on 3/1/18
Name two elements with same number of protons and neutrons
Answer
6
Vishwa
Subject: Science
, asked on 3/1/18
Q. Calculate the average atomic mass of Bromine atom. 8. CalCU!åte the average atomic mass of Chlorine atom. 9. Why do Helium , Neon and Argon have zero valency? 10. An element X has a mass number 4 and atomic number 2. Write the valency of this element. 11. In the gold fOil- experiment of Geiger and Marsden, that paved way for Ruther-fords model of an atom, approximately 1.00% of the alpha particles were found to deflect at angles greater than 50 degree. If one mole of alpha particles were bombarded on the gold foil , calculate the nurnber of alpha particles that would deflect at angles less than 50 degree.
Answer
2
Samriddhi Singh
Subject: Science
, asked on 30/12/17
Calculate the number of electrons present in 24 grams of carbon?
Answer
3
Sushmit Chakraborty
Subject: Science
, asked on 30/12/17
1. Why Euglena is called plant-animal? Why whales are not grouped under fishes?
Answer
4
Sushmit Chakraborty
Subject: Science
, asked on 30/12/17
Answer the question
Q. 6 Write correct formula using given ions.
Answer
1
Sushmit Chakraborty
Subject: Science
, asked on 30/12/17
Q 5 )Give one word for the following:-
(a) Metal present in haemoglobin.
(b) Reddish brown metal used in making electrical wires.
Answer
2
Sushmit Chakraborty
Subject: Science
, asked on 30/12/17
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Sushmit Chakraborty
Subject: Science
, asked on 30/12/17
Q3) Two elements X&Y combine in a gaseous state to form XY in the ratio of 1:
35.5 by mass. The mass of Y which combines with 2gram of X will be
(a) 7.1 gram (b) 3.55 gram (c) 35.5 gram (d) 71 gram
Answer
2
Sushmit Chakraborty
Subject: Science
, asked on 30/12/17
Q2)Law of conservation of mass was discovered by
(a) Dalton (b) Proust (c) Lavosier (d)Richter
Answer
1
Sushmit Chakraborty
Subject: Science
, asked on 30/12/17
Q1) Calculate the molecular mass(NH2CONH2).
Answer
2
Dhriti
Subject: Science
, asked on 25/12/17
Solve this:
2. Will the mass or charge on the electron change if:
(a) the potential difference in the discharge tube is increased?
(b) the pressure of the gas in the discharge tube is decreased?
(c) the nature of the gas in the discharge tube is changed?
Answer
3
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What are you looking for?
Q. (A) An element X has an atomic number 12 an atomic mass no. 26. Draw a diagram showing the distribution of electrons in the orbits and the nuclear composition of the neutral atom of the element. What is the valency of the element and why?
(B) If this element X combines with another element Y whose electronic configuration is 2,8,7. what will be the formula of the compound thus formed? State how you arrived at this formula.
Q. 6 Write correct formula using given ions.
(a) Metal present in haemoglobin.
(b) Reddish brown metal used in making electrical wires.
35.5 by mass. The mass of Y which combines with 2gram of X will be
(a) 7.1 gram (b) 3.55 gram (c) 35.5 gram (d) 71 gram
(a) Dalton (b) Proust (c) Lavosier (d)Richter
2. Will the mass or charge on the electron change if:
(a) the potential difference in the discharge tube is increased?
(b) the pressure of the gas in the discharge tube is decreased?
(c) the nature of the gas in the discharge tube is changed?