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I think the reaction that represents a balanced, double replacement chemical reaction is B which is <span>Rb2O + Cu(C2H3O2)2 → 2RbC2H3O2 + CuO </span>
Answer:
A. It is the work done when a force of 1 newton is applied to an object for a distance of 1 meter
Explanation:
The answer is <span>non-biodegradable and subject to bioaccumulation and/or bioamplification.
DDT (dichlorodiphenyltrichloroethane) is persistent, non-degradable insecticide and organic pollutant readily accumulated to soils and consequently affects organisms.
DDE (</span><span>dichlorodiphenyldichloroethylene) is non-degradable pesticide toxic to birds at the first place.
PCBs (polychlorinated biphenyls) are non-degradable organic compounds very toxic to the environment.
PBDEs (polybrominated diphenyl ethers) are non-degradable compounds very toxic to environment, even able to affect brains of animals in the development period.</span>
Answer:
C. fluorine (F) and chlorine (Cl)
D. arsenic (As) and antimony (Sb)
Explanation:
In the periodic table , all the elements are arranged according to the atomic number ,
and the elements are placed in groups and periods ,
The elements with similar chemical and physical properties are placed in a common group .
The elements present in the same group have the same number of valence electrons in the valence shell .
Hence , from the given options ,
fluorine (F) and chlorine (Cl) belongs to group 17 with 7 valence electrons in the outermost shell .
arsenic (As) and antimony (Sb) belong to group 15 with 3 valence electrons in the outermost shell .