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Thinking about the periodicity of the period 3 elements, explain the structure of the Sodium and Phosphorus Oxides and the acid-base behaviour of the Oxide solutions.

Electronegativity increases across a period because the atomic radius decreases (i.e. the valence electrons are closer to the nucleus and experience a higher attraction). This is because there are more proto...
NM
Answered by Natalie M. • Chemistry tutor
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Explain why a perfectly competitive firm will make normal profit in the long run.

A perfectly competitive market structure possess 4 defining characteristics. 1- Homegenous goods (all goods produced by different suppliers are of same quality and form, eg. Oranges) 2. No barriers to entry ...
JT
Answered by James T. • Economics tutor
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State and derive Kepler's third law

Kepler's third law states that the square of the period of any planet is proportional to the cube of its orbital radius.To derive it, two equations are required: F=GMm/r^2 and F = mv^2/r. These are Newtons l...
SB
Answered by Samuel B. • Physics tutor
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The equation kx^2+4kx+5=0, where a is a constant, has no real roots. Find the range of possible values of k.

First, if k=0 then the equation has no real roots since in this case we would have 5=0 (this is a proof by contradiction). A quadratic equation of the form ax^2+bx+c=0 has no real roots if the discriminant b...
EN
Answered by Emily N. • Maths tutor
14281 Views

What is contained within a nucleus of a cell and how is this made up or arranged

DNA is contained within the nucleus of the cell. It contains genes which are a sequence of DNA codes. Each gene codes for a protein. All the DNA is coiled into structures called chromosomes. There are 46 chr...
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Answered by Dipali P. • Biology tutor
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