Answer: 3.97 moles HCl
Explanation: Solution:
2.39x10²⁴ atoms HCl x 1 mole HCl /
6.022x10²³ atoms HCl
= 3.97 moles HCl
Answer:B
Explanation:Coefficient represents the number of units of each substance.
Answer:

Explanation:
It is given that,
Original temperature, 
Original volume, 
We need to find the temperature if the volume of the balloon to be shrink to 1.25 L.
According to Charles law, at constant pressure, 
It would means, 
T₂ = ?

So, the new temperature is 261.46 K.
Explanation:
1) Thermal and Electric conductivity
2) Metallic strength
<span>1. A scientific hypothesis can become a theory if the hypothesis is tested extensively and competing hypothesis are eliminated. A scientific hypothesis is a proposed explanation made on the basis of reasoning without any assumption. For hypothesis to be termed a scientific hypothesis, it has to be something that can be supported or refuted through carefully crafted experimentation or observation.
2. A preliminary untested explanation that tries to explain how or why thing happen in the manner observed is a scientific hypothesis. A primary trait of a hypothesis is that something can be tested and that those tests can be replicated. A hypothesis is often examined by multiples scientists to ensure the integrity and veracity of the experiment. The process can take years, and in many cases hypothesis do not go any further in the scientific method as it is difficult to gather sufficient supporting evidence. </span>