Answer:
The second one is the correct statement.
Explanation:
An atom consists of a dense, heavy, positively charged central part called nucleus. It consists of neutrons and protons.
The electrons revolves around the nucleus in circular paths. These electrons are called planetary electrons because they can be compared to various planets revolving around the sun and the nucleus is compared with sun.
In chemistry and atomic physics, the main group is the group of elements whose lightest members are represented by helium, lithium, beryllium, boron, carbon, nitrogen, oxygen, and fluorine as arranged in the periodic table of the elements
Answer: 25%
Explanation: According to the Florida Industrial and Phosphate Research Institute, Florida’s phosphate mining accounts for about 75% of the phosphate used in the United States, as well as about 25% phosphate used around the world. Although first mined in England in 1847, and used as fertilizer, In 1881, a civilian employee, J Francis Le Baron discovered Phosphate pebbles in peace river, and then, a hard rock phosphate district was discovered in north central Florida after that which began the Phosphate mining industry in Florida. Phosphorus rock supplies the phosphorus element in the fertilizer mix of nitrogen-phosphorus-potassium that is used as fertilizer to aid in growth of plants.
Activation of energy is the foundation of chemical being react in a solution. If activation energy is not reached then no reaction would happen.
