Answer:
.
Explanation
In HX , X is more electronegative than Y so HX will ionise more because of ionic bond between H and X . On the other hand H₂Y will be less polar as compared to HX so it will ionise to a lesser extent . Hence Ka will be more for HX . Ka represents the degree of ionisation of acid . Higher the ionisation , higher is the value of Ka . H₂Y which is less polar will ionise less and hence it will have lesser value of Ka .
Hence H₂Y will have value of 10⁻⁷ and HX will have value of ka equal to 10⁹ .
Answer:
semiconducting,tellurium
Explanation:
just completed the assignment
Answer: Alpha radiation
Explanation: Alpha decay : When a larger radioactive nuclei decays into smaller nuclei by releasing alpha radiation, the mass number and atomic number is reduced by 4 and 2 units respectively.

Beta decay : When a larger radioactive nuclei decays into smaller nuclei by releasing beta radiation, the atomic number is increased by 1 unit.

Gamma decay : When a larger radioactive nuclei decays into smaller nuclei by releasing gamma radiation, the mass number remains same.

Answer:
B. an element
Explanation:
An atom is smallest indivisible particle that takes part in a chemical reaction. Different atoms due to the number of their protons called atomic number gives an element. Every element is a singular atom on it's own. Combination of atoms leads to the formation of molecules and compounds.
When compounds mix together without an actual chemical change, a mixture forms.
Elements are distinct substances that cannot be split up into simpler substances. They are usually made up of only one kind of atom.