Answer:
THEY ALL INVOLVE FIGHTING PATHOGENS
Explanation:
The immune system which is involved in defending the body against infections are diseases involves three lines of defense which are all involved in fighting against pathogens. Pathogens are invaders which when introduced into the body causes harm and therefore makes us sick. The body's first line of defense includes the physical barriers such as the skin, mucous membrane; chemical barriers such as tears, saliva, gastric acid in the stomach. These helps to keep the pathogens from entering the delicate parts of the body and once the pathogens find their way out of the reach of the first line of defense, the second line of defense is initiated. This includes inflammatory effects, swelling, redness, phagocytosis by neutrophils and macrophages. The third line of defense is the actions of lymphocytes which acts on invading microbes. The lymphocytes are of two types; the B and T cells. B cells produces antibodies which fight the antigens and T cells attack the infected cells of the body. There is also the memory cells which keeps information about the invading microbes for future attacks. This enables the body to respond swiftly when next the same type of pathogens attack.
Answer:
a. 4 sig figs
b. 3 sig figs
c. 2 sig figs
Answer:
Groups 14, 15, and 16 have 2,3, and 4 electrons in the p sublevel (p sublevel has 3 "spaces" AKA orbitals), because Hunds says one in each orbital before doubling up if you had 2 electrons, group 14, they would both be in the first orbital, with 3 electrons, group 15, two in the first orbital one in the 2nd none in the 3rd. With 4 electrons, group 16, then you would have 2 in the first 2 orbitals and NONE in the 3rd.
Explanation:
If you are in group 13 you only have 1 electron so it can only be in one orbital. with group 17, you have 5 electrons, so 2 in the first 2 in the second and 1 in the 3rd, correct for Hunds rule anyway. Noble gasses, group 18, have 6 elecctrons, so every orbital is full any way you look at it.
