Shameeka is studying for an exam. She took the notes below about calcium and chlorine, which are known to form ionic bonds. Calcium, which is a metal, donates 2 electrons to chlorine.
The individual calcium atoms become ions with a negative 2 charge.
The bond between calcium and chlorine makes the atoms stable.
Calcium and chlorine attract each other.

Which best describes Shameeka’s error?

Calcium is a metal, so it donates protons, not electrons.
The individual calcium atom has a positive, not negative, 2 charge.
The bond formed makes the atoms unstable, not stable.
Calcium and chlorine repel, not attract, each other.

Which of the following statements is correct in hour our immune system responds to a potential pathogen? a. the adapted immune system will call on the innate immune system to destroy the pathogen. b. b cells will start reading the antigen code immediately and call t cells to assist in destroying the pathogen. c. the skin will be the first line of defense, and then the many phagocytes in the bloodstream will attempt to consume the possible pathogen. d. the t-cells in the adapted immune systems are the first to recognize the pathogen vaccines are weakened forms of disease causing microorganisms, which are given to patients to prevent disease. after the vaccine is administered, the immune system responds by creating a(n) to recognize the a. antigen, antibody b. antibody, antigen c. antibody, antibiotic d. antibiotic, antibody