Answer;
-Pure chemical substance and element
Explanation;
-Pure substances are substances that are made of only one type of atom or molecule.A pure substance can be either an element or a compound, but the composition of a pure substance doesn’t vary.
-An element is a pure substance that cannot be broken down into different types of substances by chemical means. All elements are pure substances. An element is composed of a single kind of atom. An atom is the smallest particle of an element that still has all the properties of the element.
-Tungsten is an element and therefore a pure substance.
Answer:
Stem cells are cells with the potential to develop into many different types of cells in the body. They serve as a repair system for the body. There are two main types of stem cells: embryonic stem cells and adult stem cells
Explanation:
Totipotent (or Omnipotent) Stem Cells.
Pluripotent Stem Cells.
Multipotent Stem Cells.
Oligopotent Stem Cells.
Unipotent Stem Cells.
<span>A food handler is anyone who handles either
food or surfaces that are likely to be in contact with food such as plates,
bowls or cutlery. Therefore, he is responsible to ensure that food is safe to
eat, monitor a control such as to check and record food temperatures, keep
himself, his work clothes and work place clean. In addition, he need to report
any flu-like symptoms, skin infections, or open wounds. </span>
Answer:
Immigrants may be defined as the individuals that comes from some other country but are the permanent resident of some other country. The individual might move for the jobs and education.
The immigrants might flock to the urban neighborhood and can settle on the basis of the their ethnicity. These neighborhood provide jobs to the immigrants and they had poor working conditions. The immigrants were underpaid. The mutual aid societies are formed in which immigrants pay dues and and the society pay for their elevation. The Americans and immigrants suffers from the pollution, crime and overpopulation.
Mutalistic Relationship <span />