I believe it’s A................
Answer:
The mass number (A) of an atom is the total number of protons and neutrons in its nucleus. ... Because electrons have virtually no mass, just about all the mass of an atom is in its protons and neutrons. Therefore, the total number of protons and neutrons in an atom determines its mass in atomic mass units (Table 4.5. 1).
This has only only three sig figs because it is 546.000 the zeros are just place holders so thus meaning they are not significant. It is just another way to write 546 because in that number there is also 3 sig figs. They are just trying to throw you off. Just watch out because if the example is 540 then it is just two significant digits, and it were to be 540. then it be three cause that "." makes the zero significant. <span />
<span>A compound is a combination of elements chemically combined. Briefly explain why a beaker containing sand and water is a mixture although sand itself is a pure substance. Because it's a combination of two or more substances. ... Briefly explain why a compound has <span>characteristic properties</span></span>
Answer:
the amount of soduim phosphate is will be 52 percemt