Because the copper roofs, have been outside for a while and oxidization has occurred.
When metals become oxidized they rust, but when copper becomes oxidized, it turns greenish.
So copper roofs oxidize and turn green from being outside and a copper square doesn’t if it’s inside.
Ionic bond is a type of chemical bond that refers to the bonding of <span>oppositely charged ions (anions and cations) because of attraction and the </span>transfer of valence electron(s) between atoms. Cation is the metal that loses electrons and become a positively charged cation, and anions are
the nonmetal that accepts those electrons to become a negatively charged
anion.
According this explanation, an ionic bond is:
B. the force that holds the valence electrons to the atom
Your answer is C forms of the same element that differ in the number of neutrons in each atom because if the number of neutrons change the whole element changes.
Scientists prevent the nonpolar perfluorocarbons
in Oxygent from separating from the water by adding surfactant.
<u>Explanation:</u>
The collection of oxygen from lungs and transporting it all those tissues present in the human body and taking carbon dioxide back to lungs are the main functions of the hemoglobin. But, instead of this hemoglobin, When perfluorocarbons
, a nonpolar chemical is used to perform the same function for the oxygen transportation, the nonpolar chemical may not mix well with the water when this perfluorocarbons is taken through a water-based saline
.
For this purpose an addition of a chemical called surfactant is done. This will enhance the chemical bonding between the non polar chemical and water. The perfluorocarbons spreads into some droplets and gets coated with this bonding substance. Thus it gets attached to the water.
