Answer:
Three (3).
Explanation:
The octet rule is a rule in chemistry that states that, chemical elements would either gain or loss electrons in their outermost shell in order to attain a stable electronic configuration i.e having eight (8) valence electrons in their outermost shell such as chemical elements found in group 8 (2-8-8) known as noble gas.
A phosphorus atom needs to gain three (3) electrons to achieve a full octet because the atomic number of phosphorus is 15 and as such it has the electronic configuration of 2-8-5 and needs three electron in order to become a stable element.
Answer: decantation and screening
Explanation:
<span>(v1)^2=(v0)^2-2ad; v1= final velocity; v0= initial velocity; a=gravitational constant;d=distance
Since the stone was dropped we know v0=0.
(v1)^2=2ad
(136)^2=2(32)d
d=(136)^2/(2*32)
d=289ft</span>
Answer:
b) Expansion
Explanation:
In science, matter can be defined as anything that has mass and occupies space. Any physical object that is found on earth is typically composed of matter. Matter are known to be made up of atoms and as a result has the property of existing in states.
Generally, matter exists in three (3) distinct or classical phases and these are; solid, liquid and gas.
A physical change can be defined as a type of change that involves an increase or decrease in the volume of a physical object (object). Also, this change can be reversed to the original state under certain conditions.
The increase in volume of matter that occurs when matter is heated causes an expansion.
This ultimately implies that, when a physical object (matter) is heated for a specific period of time, it result in an increase in the volume of the object; this phenomenon is generally referred to as expansion.
On the other hand, a decrease in volume of a physical object (matter) as a result of heat is known as contraction.
