A C and D are all correct, Helium and Hydrogen only have a 1s orbital, and helium has 2 protons, while hydrogen has 1, and finally Hydrogen has no neutrons while helium has 2. Helium does not however have 8 valence electrons as the 1s orbital can only hold 2, meaning B is the “correct” (false) answer.
Answer: arrangement of constituent particles makes glass diff. from quartz. Glass-short range order of particles.
Quartz-Long range of particles.
If quartz is heated and cooled rapidly it can be converted to glass.
The variable "air pressure inside the football" in this experiment is quantitative and dependent variable. Hence, option D is correct.
<h3>What is the dependent variable?</h3>
The dependent variable is the variable that is being measured or tested in an experiment.
In the experiment, the scientist filled the footballs with fix quantity of pressure which was then kept for 12 hours. After 12 hours the pressure inside the footballs was again measured. Pressure here is a quantitative variable.
Since the air temperature is an independent variable. The pressure being the dependent variable depends upon the temperature of the air.
Independent variable; The variable which does not depends upon any other variable.
Dependent variable; The variable which depends upon the independent variable or varies with the change independent variable.
Qualitative variables are variables which cannot be expressed in form of numbers. They generally convey the characteristic, category, quality or type.
Whereas Quantitative variables are the variables which can be expressed in the form of numbers. These are the variables which exist along the continuous sequence.
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Charcoal is the sample of this drawing medium have been dated back to 30,000 BCE and is denoted as option B.
<h3>What is Charcoal?</h3>
This is referred to a black carbon residue which is heated in insufficient oxygen to give it a light weight.
It is used for drawing and has been in existence for as long as 30,000 BCE hence the reason why it is the most appropriate choice.
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