Answer:
<em>The correct option is A) The atom has changed over the years.</em>
Explanation:
Option A is not correct because an atom does not change. It remains the same always. The structure of an atom will always contain neutrons, protons and electrons.
Scientific theories tend to change over time as new information is brought up. Novel techniques lead to more advanced experiments and results. As a result, a scientific theory is subjected to change whenever evidence is found for a new theory which challenges the older one.
The atomic theory has changed many times due to novel scientific techniques and experiments.
Answer: (C) Statements (i) and (iii)
Explanation: According to byjus.com, group VII elements are known as Halogens.
Not only that, but bbc.co.uk says " Atoms of group 7 elements all have seven electrons in their outer shell. This means that the halogens all have similar chemical reactions ."
It may just be (b) though as these are chemical reactions.
Answer: 
Explanation:Bond energy of H-H is 436.4 kJ/mole
Bond energy of C-H is 414 kJ/mol
Bond energy of C=C is 620 kJ/mol
Bond energy of C≡C is 835 kJ/mol
= {1B.E(C≡C)+2B.E(C-H) +1B.E(H-H)} - {1B.E(C=C)+4B.E(C-H)}
Answer:
An ideal gas is a theoretical gas composed of many randomly moving point particles that are not subject to interparticle interactions. The ideal gas concept is useful because it obeys the ideal gas law, a simplified equation of state, and is amenable to analysis under statistical mechanics.
Answer:
You can view more details on each measurement unit: molecular weight of Copper(I) Oxide or grams The molecular formula for Copper(I) Oxide is Cu2O. The SI base unit for amount of substance is the mole. 1 mole is equal to 1 moles Copper(I) Oxide, or 143.0914 grams.
Explanation:
