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The really BIG social implication between fossil fuels and biofuels is competition for available agricultural land and crops. Fossil hydrocarbons store solar energy that arrived on the Earth 250 to 200 million years ago. That's 50 million years of accumulated solar energy that we want to release...

@kractus We are looking for the points where the rate of change of the area of the loop is maximum. That will give the maximum ΔΦ/Δt That would be at points A or C. We are looking for an induced current that flows clock-wise in the loop from P to Q. The static part of the loop of wire P-G-Q is...

In order to provide subject advice, we need to know your career direction. You said you want to enrol in engineering, but you didn't say which discipline.

@Interdice . That essay answer was a total waste of space. I don't know why they bothered printing it. Centrifugal force doesn't exist - it is what we call a fictitious force and you won't find it mentioned in the Physics syllabus. The centripetal force definitely exists. Here is a model answer...

That is correct. This is a very difficult question to give to high school Chemistry students. It is bad enough that we have to learn about spin-spin coupling to reveal the fine scale structure in proton-NMR spectra. But then to ask students to remember the exceptions to the rule is really cruel...

I will attempt to give you a new direction in your learning. You have written a very clear explanation of your dilemma, and this deserves a clear answer. It is never too late to try a different way of learning. Both Mathematics and Science are highly structured in their theory of knowledge...

The NESA rules are quite clear - only one of those written examinations can be reported to NESA as part of the school-based assessment. That written assessment can not contribute more than 30 per cent of the school-based assessment. Schools can conduct other written assessments if they so...

Students are not required to memorise flame test colours for the HSC Chemistry examination. The syllabus does not require it, and even if a question about flame tests was included, the data would have to be provided either in the formula sheet or in the body of the question. The HSC Chemistry...

Good question. This ion has the ability to be both a proton donor and a proton acceptor. That tells us something about how this ion is going to behave in water. If you try to lower the pH of the solution by adding more H3O+, it will react with them, and if you try to raise the pH of the solution...

No. The amount of OH- and H3O+ ions present is very small, approximately 10-7 M.L-1. These equations are describing how the pH of water will be altered by the presence of this ion (not by much it would seem, because this ion is amphiprotic) These equations are describing equilibrium.

Resonance structures in Chemistry refers to bonding electrons moving rapidly between positions of roughly equivalent potential energy. So if there are two structural isomers that differ only in the position of a double bond (as in the amide that you mentioned) then both structures are equally...

Solubility is defined as the number of grams of anhydrous substance that will dissolve in 100g of water at 25oC. You should learn these three terms that describe solubility. Soluble : at least 1 g will dissolve in 100 g of water Sparingly Soluble: at least 0.1 g will dissolve in 100g of water...

Yep, agree. Think of the lamp as if it was an electrical resistor. The power output of the lamp is equal to the product of the voltage times the current. P = V x I. Assuming the resistance R of the ionised gas in the lamp is fairly constant, then P = V2/R A small increase in the voltage will...

I agree mostly with the account given by @carrotsss which is very well done. A good description of dynamic equilibrium. However, there is one feature missing - the transport problem. The radioactive Pb2+ ions will leach out of the surface of the solid and be replaced with non-radioactive Pb2+...

When you set up a multidimension array, you have to initialise "dim" the array and define explicitly how many dimensions it will hold and what data types it will hold. Then sufficient memory will be reserved to hold this size of array. It could be a 4-dimensional array. Then you can read or...

Rule 1. All glassware has to be rinsed with de-ionised water, to make sure it is not contaminated. Rule 2. Every vessel that is volumetric, i.e. it has lines scribed on the outside, must get rinsed a second and a third time with what ever solution is going in next. That means burette and pipette...

The worst teacher shortages are in STEM subjects. The Sydney Morning Herald reported on 7th October 2021 the results of a leaked report from inside the NSW Education Department...

Unfortunately, research has shown that in New South Wales schools, 41% of Physics teachers are teaching "out-of-field", i.e. outside of their area of qualification. It is one of the worst subjects for teacher shortages. Schools can't attract properly qualified Physics teachers. The metropolitan...

Yes, that is what we believe. The negative charge density of the non-bonding electron pair at the nitrogen is strongest when the adjacent carbon is bonded to carbon or hydrogen (the electronegativity of C and H is about 2). When oxygen (electronegativity of 3.44) fills a double bond on the...

Yes, there are differences in the pH (or pKa) of aqueous solutions of the various amines, but the difference is not strong. Here is some data for a series of amines: methylamine (primary) pKa = 10.64 dimethylamine (secondary) pKa = 10.71 trimetylamine (tertiary) pKa = 9.77 As you can see...