In chemistry the need for standards when measuring quantities are in place for accurate measurement that is recognized world wide. This way, no matter what language people use, they will always understand there standards.
Answer:
The correct answer is C. element
Explanation:
The sample cannot be an element because an element - or <em>elemental substance</em> - cannot be decomposed into simpler substances. Thus, it cannot be composed by differents types of atoms. For example, an element is carbon (C).
As the sample contains <u>three types of atoms</u>, it can be a compound, a molecule or a mixture, because they can be composed by different types of atoms - of different chemical elements. For example, the sample could contain the element carbon (C) combined with other elements, for example oxygen (O) or hydrogen (H), amoing others.
The unsaturated zone is the portion of the subsurface above the groundwater table. The soil and rock in this zone contains air as well as water in its pores. ... Unlike the aquifers of the saturated zone below, the unsaturated zone is not a source of readily available water for human consumption
Answer:
- 53 protons
- 131g
- Iodine
- Halogens
Explanation:
atomic no. = no. of protons
= 53 proton
mass = no. of protons + no. of
neutrons
= 53 + 78
= 131
