A quantitative observation must be a measurement of some sort. (Something including numbers). Qualitative, on the other hand, is when you are using words to describe what has happened.
Explanation:
Quantitative observations are performed with devices such as rulers, balances, measured cylinders, beakers, and regulators. These results are measurable,using one or more senses to gather knowledge. information that doesn't involve numbers or measures. the process of making an understanding based on observations and previous knowledge. Quantitative investigations always involve numbers.
Answer : The molecular weight of a gas is, 128.9 g/mole
Explanation : Given,
Density of a gas = 5.75 g/L
First we have to calculate the moles of gas.
At STP,
As, 22.4 liter volume of gas present in 1 mole of gas
So, 1 liter volume of gas present in 
mole of gas
Now we have to calculate the molecular weight of a gas.
Formula used :
Now put all the given values in this formula, we get the molecular weight of a gas.
Therefore, the molecular weight of a gas is, 128.9 g/mole
Answer:
Some things that were wrong with Rutherford's model were that the orbiting electrons should give off energy and eventually spiral down into the nucleus, making the atom collapse. Bohr proposed his quantized shell model of the atom to explain how electrons can have stable orbits around the nucleus. To remedy the stability problem, Bohr modified the Rutherford model by requiring that the electrons move in orbits of fixed size and energy.
Explanation:
I think d not sure tho but hope it helps
