Sources of Energy — Science STD 10 — Question

Give one example of a combination reaction which is also endothermic.

When a magnesium ribbon is heated, it burns in air to form magnesium oxide. Write a balanced chemical equation for this reaction. Name:

1. Substance oxidised, and
2. Substance reduced.

Which produces more energy: nuclear fusion or nuclear fission?

Buckminsterfullerene is a spherical molecule in which 60 carbon atoms are arranged in interlocking hexagonal and pentagonal rings of carbon atoms.

1. How many hexagons of carbon atoms are present in one molecule of buckminsterfullerene?
2. How many pentagons of carbon atoms are present in one molecule of buckminsterfullerene?

A ray of light strikes a plane mirror at an angle of 40° to the mirror surface. What will be the angle of reflection?

What part does the diet play in helping us to have a healthy thyroid gland?

Give the constituents and one use of brass.

The atomic number of an element X is 8 and that of element Y is 12. Write down the symbols of the ions you would expect to be formed from their atoms.

Name the substance obtained by the action of chlorine on solid (dry) slaked lime.

1. Which simple food is prepared first in the process of photosynthesis?
2. Name the food which gets stored in plant leaves.