Alkali metals, such as potassium, must be transported in special sealed containers because they have the ability to burn or explode upon contact with water due to their high reactivity. This is an example of a
A. None of these
B. Chemical change
C. Chemical property
D. Physical change

Alkali metals include lithium (Li), sodium (Na ) , potassium (K), rubidium (Rb), caesium (Cs), and franc (Fr) chemical elements. They shape Group 1, which is part of the s-block of a periodic table, along with hydrogen. All alkaline metals have their outermost electron in s-orbital, which gives very similar characteristic properties. This common electron configuration. Alkali metals, in addition, are the strongest indicators of group patterns in properties in a standard table and have well-characterized components with related behaviour. After its leading member, this family is also known as the lithium family.

in scientific notation, the value of the  speed of light in a vacuum

  will be written as 2.995 * 10^8. when this value is represented in the form of

  a * 10^b, then, a = 2.995 and b = 8.

the value of the speed of light in a vacuum given above can also be rounded up to approximately 300000000. in this case, the scientific notation will be written as 3 *10^8.