We can see that about 97% of the total mass of human body can be attributed to the combined mass of four elements. Can you identify them?

Fill in the blanks : Human body is mainly formed of the combined mass of _________ elements.

Fill in the blanks : Water cosntitues about _________ of the total mass of human body.

Can the equivalent mass of an element be zero? Explain.

Name the diseases Aedes mosquitoes spread. How can we identify them?

If the density and the dimension of unit cells of a metal are known, then how can you determine the atomic mass of the element?

Differences in characteristics of the same organ are noted in human populations. Write two properties you know of like this. How can you eliminate the social misconception about determining the gender of a child?

The density of the material of a cube can be estimated by measuring its mass and the length of one of its sides. If the maximum error in the measurement of mass and length are 0.3% and 0.2% respectively, the maximum error in the estimation of the density of the cube is approximately