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How would you correctly carry out a flame test, and what colour would potassium yield, and what colour would lithium yield?

Answer First a wire loop is cleaned with diluted hydrochloric acid, which is then dipped into the sample metal or solution. This is then held over an open flame and the colour emitted is observed. The colour...
CK
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How can I solve quadratic equations by completing the square?

When we have a quadratic (ax 2 + bx + c = 0) we can "complete the square" to solve for x. For example x 2 + 8x + 7 = 0. First look at the x 2 + 8x, in particular the coefficient of x, "b"...
TB
Answered by Thomas B. • Maths tutor
4171 Views

Explain the pull factors of counter-urbanisation.

Counter-urbanisation is the movement from city to rural area (centrifugal movement). Firstly, it is quieter in suburban/rural areas with less traffic, congestion and higher living standards. This is especial...
SS
Answered by Svenja S. • Geography tutor
12245 Views

What are moles in Chemistry?

The moles is the amount of a substance that we are measuring, its like measuring how many coins I have in my pocket, but instead how many atoms of an element we have. We use the equation moles=mass/RMM to wo...
LP
Answered by Lucy P. • Chemistry tutor
4839 Views

Find the value of X and Y if X^2 + Y^2 = 13 and 2X + Y = 1

Firstly, since only one equation is linear, substitution must be used. This will allow us to make a quadratic equation with one variable and solve for X and Y. To do this, I will make Y the subject of the fo...
AS
Answered by Alexis S. • Maths tutor
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