The correct answer is B. The nitrogen in the nitrogen cycle originate from the atmosphere. It forms approximately 78% of the Earth's atmosphere. However, this form is not usable because it is in its most stable form therefore unreactive. This nitrogen gas needs to be converted into nitrate compound for it to be usable. Then, the nitrogen cycle starts.<span />
Answer: C) Elements and pure compounds are homogeneous materials because they have a uniform composition throughout.
Explanation: Element is a pure substance which is composed of atoms of similar elements. Compound is a pure substance which is made from atoms of different elements combined together in a fixed ratio by mass.
Elements are compounds form homogeneous materials as they have uniform composition throughout and the components are evenly distributed throughout the material.
Mixtures are heterogeneous materials as they do not have uniform composition and the components are not evenly distributed throughout the material.
The relative atomic mass is the weighted average mass of elements relative to 1/12th the mass of a 12-C atom.
Isotopes are atoms of the same element with different masses , in other words different numbers of neutrons.
Relative atomic mass =sum of (mass x percentage )
R.a.m = 62.9300 x 69.15% + 64.9200 x 30.85%
= 43.52 + 20.03
= 63.55 amu
A Velocity Vector represents the rate of change of the position of an object. The Magnitude of a Velocity vector gives the speed of an object while the vector direction gives its direction.
The answer would be true because it is not possible for aspirin to have only one compound if it does many things.
