Which of the following pairs of elements can be joined by a covalent bond? A. Na and C
B. Mg and Cl
C. O and N
D. N and Be

What is a main difference between a mixture and a pure substance? a mixture is only a liquid, but a pure substance can be in any state.a mixture looks the same throughout, but a pure substance does not.1 a mixture can vary in composition, but a pure substance has a set composlo a mixture can be made up of a single compound, but a pure substance car