Answer:
The adaptive (also called humoral or specific) immune system is typically only involved in immune responses to bacteria, bacterial toxins and virus antigens. It involves the production of antibodies (also called immunoglobulins) against a specific target. The target of an antibody is called an antigen.
Sulfur has two filled energy levels and six electrons on the third energy level. The corresponding electron configuration is A.
B is incorrect because there are no p orbitals at the first energy level, ie, no 1p orbitals. C is incorrect because the 4s1 electron would spontaneously drop into the 3p orbitals. D is incorrect because the 3d electrons would spontaneously drop into the 3p orbitals.
Answer:
The atomic mass of element is 65.5 amu.
Explanation:
Given data:
Abundance of X-63 = 50.000%
Atomic mass of X-63 = 63.00 amu
Atomic mass of X-68 = 68.00 amu
Atomic mass of element = ?
Solution:
Abundance of X-68 = 100-50 = 50%
Average atomic mass = (abundance of 1st isotope × its atomic mass) +(abundance of 2nd isotope × its atomic mass) / 100
Average atomic mass = (50×63)+(50×68) /100
Average atomic mass = 3150 + 3400 / 100
Average atomic mass = 6550 / 100
Average atomic mass = 65.5 amu.
The atomic mass of element is 65.5 amu.
The most likely formula for an oxide formed between group 1a atom X and oxygen would be
X2O. - X is group 1a atom.
