Answer:
Hydrogen.
Explanation:
Hydrogen is the simplest chemical element that exists. The symbol for the chemical element Hydrogen is "H" and it is a colourless, tasteless, odorless, and highly flammable gas.
Hydrogen is a chemical element found in group (1) of the periodic table and as such it has one (1) electrons in its outermost shell. Therefore, Hydrogen has an atomic number of one (1) and a single valence electrons because it has only one proton and one electron in its nucleus.
Based on the octet rule which states that atoms of chemical elements gain, lose or share electrons so as to have eight (8) electrons in their valence shell. Therefore, atoms of chemical elements bond in order to attain the electronic configuration of a noble gas i.e a full valence shell which comprises of eight (8) electrons.
However, the chemical element "Hydrogen" is an exception to the octet rule because it is only able to hold a maximum of two (2) valence electrons in its outermost shell to become full.
<em>Hence, Hydrogen is an element which does not want to have eight valence electrons. </em>
<h2>Active and Passive Immunity</h2>
Explanation:
- Immunity can be obtained distinctly and Recovery from clinical tetanus doesn't bring about assurance against future disease by <em>active or passive immunization</em> and recovery from the clinical<em> for example, immunization, immunoglobulin treatment, or move of maternal antibodies through the placenta</em>
- Active inoculation stimulates the <em>immune system to deliver antibodies against a specific irresistible specialist</em>
- <em>Active immunity</em> can emerge normally, as when somebody is presented to a pathogen.<em> For example,</em> a person who recuperates from a first instance of the measles is <em>insusceptible to advance immunity</em>
