Answer:
Percentage of oxygen = 30%
Percentage of carbon = 30%
Percentage of hydrogen = 40%
Explanation:
Formula:
Percentage of element = given amount / total amount × 100
Given compound:
C₆H₈O₆
Number of atoms of carbon = 6
Number of atoms of hydrogen = 8
Number of atoms of oxygen = 6
Total number of atoms = 20
Percentage of carbon = 6/20 × 100
Percentage of carbon = 30%
Percentage of Hydrogen = 8/20 × 100
Percentage of Hydrogen = 40%
Percentage of oxygen = 6/20 × 100
Percentage of oxygen = 30%
If the angle is either 0 or 180, that means that there is either negative or positive work, so A and D are not correct.
If the angle is 45, then there is still some work involved.
The only option where there is no work done by a force is B. when the angle is between the force and displacement is 90.
The correct answer is:
b: Heluim
Explanation:
The caffeine contains:
carbon , nitrogen , oxygen ,
hydrogen.
Caffeine is a primary nervous system energizer of the methylxanthine class. It is the world's most universally consumed psychoactive drug. Unlike many other psychoactive elements, it is fair and unlimited in nearly all parts of the world. Caffeine can be arranged as an alkaloid, a term used for substances originated as end results of nitrogen metabolism in some plants.
Answer:
Group 7A
Explanation:
The group 7A elements consists of the most reactive non-metals on the periodic table.
This group is known as the group of halogens. They consist of element fluorine, chlorine, bromine, iodine and astatine.
- The elements in this group have the highest electronegativity values.
- They have 7 valence electrons and requires just one electron to complete their octets.
- This way, they are highly reactive in their search for that single electron.
