Question

A ball is thrown vertically upwards with a velocity of 49m/s. Calculate the (a) Maximum height to which it rises.
(b) Time taken by the ball to return to the surface of the earth.
SECTION – D
34. Elements X and Y have atomic number 11 and 8, respectively. Mass number of X is 23 and mass number of Y is 16.
a) Find the number of protons, electrons, neutrons in them.
b) Write their electronic configuration.
c) Are they metals or non-metals? Justify.
d) How many valence electrons are there in each atom?
e) What type of ions are formed from these atoms during chemical reactions? Write symbols of the ions formed.
OR
a) Explain the observations and conclusions of Rutherford’s (alpha) α-particle scattering experiment.
b) Write the features of Thomson’s Atomic Model.
c) State any two uses of isotopes.
35. Given below is a diagrammatic sketch of electron microscopic view of an animal cell:
(a) Label the parts indicated by lines as 1 to 14.
(b) Give two reasons to support that it is an animal cell.
(c) How many mitochondria are shown in the diagram?
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Answer 1

Answer:

same time as it reaches up