Periodic Classification of Elements — Science STD 10 — Question

State whether the following statement is true or false:
Human beings have evolved from chimpanzees.

What happens to the image when the object is moved away from the mirror gradually?

Suggest one word for each of the following statements/ definitions:
The physical factors like temperature, rainfall, wind and soil of an ecosystem.

What would be the ratio of chromosome number between an egg and its zygote?

Write the structural formula of propene.

What is common for cuscuta, ticks and leeches?

State whether human beings reproduce by sexual method or asexual method.

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 lens which can concentrate sun’s rays to a point and burn a hole in a piece of paper.