Answer:
This question is incomplete
Explanation:
This question is incomplete, however, element R and element Q having the same number of valence electrons means they belong to the same group in the periodic table which is the reason for there similar chemical behavior (as elements in the same group tend to have the same chemical properties).
Element R having fewer energy level (or electron shell) than element Q shows element R has fewer number of electrons than element Q and can be found earlier in the periodic table (or group in particular) when compared to element Q
Asteroids are made up of metals and rocky material , while comets are made up of ice ,dust and rocky material.
Because if you change two things then you do not know which one has affected or altered the dependent variable. if you only change one then you know what exactly changed and why
(ANS1)— P4 + 5O2 ---> 2P2O5
(ANS2)— C3H8 + 5O2---> 3CO2 + 4H20
(ANS3)— Ca2Si + 4Cl2 ---> 2CaCl2 + SiCl4