Answer:
D: to transport materials through the body.
Explanation:
A: to bring oxygen into the lung. is incorrect because it's respiratory system
B: to put carbon dioxide into all the blood vessels carbon dioxide is exhaled out of the body
C: to expel waste products from the body. is excretory system
Answer:
The increasing order of conductivity is O< Ge< Mn.
Explanation:
Electrical conductivity is defined as the measure of the ability of a material to conduct electrical current through it. The conductivity depends on the atomic and molecular structure of the material.
Metals are good conductors because they have a structure with many electrons with weak bonds, and this allows their movement instead non-metals have between four and eight valence electrons, which lack this tendency.
The conductivity increases in the periodic table from top to bottom and from right to left.
oxygen is a nonmetal therefore it is a bad conductor.
Germanium is a metalloid whose conductivity is greater than a nonmetal and worst than a metal.
Manganese is a metal,in this case, it is a good conductor.
Answer:
beta minus emission
Explanation:
Beta radiations:
Beta radiations are result from the beta decay in which electron is ejected. The neutron inside of the nucleus converted into the proton an thus emit the electron which is called β particle.
The mass of beta particle is smaller than the alpha particles.
They can travel in air in few meter distance.
These radiations can penetrate into the human skin.
The sheet of aluminum is used to block the beta radiation
²³⁹₉₃Np→ ²³⁹₉₄Pu + ⁰₋₁e
The beta radiations are emitted in this reaction. The one electron is ejected and neutron is converted into proton.
