<u>Answer:</u>
The mass of the atom depends on the sub atomic particles present in the nucleus of an atom.
That is, the protons and the neutrons.
Electrons are present around the nucleus and the mass is negligible since its mass is very very less.
<em>mass of a proton = 
</em>
<em>mass of a neutron = 
</em>
<em>mass of an electron = 
</em>
Mass number represents the mass of one particular isotope and it is a whole number for example, 
Mass number is 13 and atomic number is 6 for the carbon isotope C-13.
Atomic mass is different from mass number and it is a fraction since it is the average atomic mass of all the isotopes of an atom.
Atomic mass of C is 12.011 amu which we see in the periodic table is the average atomic mass of isotopes C-12, C-13 and C-14.
The correct is this because they said
Answer:
Zn, Cu, Fe, Mn, Co, Mo
Explanation:
Biogenic elements are chemical elements constantly present in organisms and having definite biological significance(Bowen, 1966).
There are many of these biogenic elements in nature. Among the elements of the d-block, Zn, Cu, Fe, Mn, Co, Mo are worthy of mention among others.
Free ions of d- block metals are not found in the body. The elements are present in the form of bioinorganic complexes of the respective metals. They commonly exist as co-factors of proteins that carry out essential biological functions.
Liquid petrol does not ignite spontaneously when exposed to the air because there is not enough molecules that contains energy to reach the activation energy. As a result, the reaction cannot proceed and a supply of energy should be added for the reaction to occur.
Sun spots- dark circles on the sun’s surface that I believe are areas of cooler temperatures.
Solar flares- arcs of fire that leap from the sun’s surface. Nothing special, they’re a daily roumaine for the sun
