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What is the atomic number of an atom and How many electrons are there in an atom of Nitrogen when it has an atomic number of 7?

The atomic number is equal to the number of protons in an atom. The number of protons in an atom is equal to the number of electrons in an atom so the number of electrons in nitrogen is 7 electrons
TA
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What is the difference between Pretérito Perfecto (preterite tense) and Pretérito Imperfecto (imperfect tense)?

The preterite tense (or pretérito perfecto) refers to an event that occurred once in the past, whereas the imperfect tense (pretérito imperfecto) refers to an event that occurred continuously or more than on...
AO
Answered by Alma O. • Spanish tutor
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If there are 20 marbles in a bag and 1/5 are red, what fraction are red if 1 more red marble is added?

Originally, 1/5 of 20 marbles are red. 1/5 of 20 = 4. If i add 1 more we have 5 red marbles. 5/20 = 1/4.
LO
Answered by Liam O. • Maths tutor
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How do I structure an A-Level History essay?

When writing a history essay the basic structure that you learnt at GCSE can be employed at A-Level: Introduction - Point 1- Point 2 - Point 3 - Conclusion. However, when writing at A-Level standard new comp...
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Answered by Josephine A. • History tutor
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How to integrate ∫〖3x/√(1-x^2 ) dx〗?

We will use integration by substitution to solve this integral. Let 1-x^2=sin^2(u) This means that: x^2=1-sin^2(u)=cos^2(u) (using the trigonometric identity sin^2(x)+cos^2(x)=1). Therefore, x=cos(u). If we ...
AO
Answered by Alma O. • Maths tutor
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