Physical Chemisty 1

Question 1

What is the atomic number

Answer 1

The number of protons in the nucleus

Question 2

What is the mass number

Answer 2

The number of protons plus neutrons in an element

Question 3

Define isotope

Answer 3

Atoms with the same number of protons but different number of neutrons

Question 4

What happens in a time of flight mass spectrometer

Answer 4

1) the substance in the sample are converted into positive ions, accelerated to a high speed so that all particles have the same kinetic energy and then are attracted to the detector which has a negative charge .

Question 5

How do you work out mass in a mass spectrometer

Answer 5

Mass - the time taken for the ions to reach the detector . Lighter ions will get there quicker

Question 6

What is the equation for time of flight

Answer 6

Time = distance x square root (mass/2ke)

Question 7

How to work out mass in time of flight

Answer 7

Relative atomic mass/ avogadros constant

Then divide by a thousand

Question 8

How are hydrogen bonds formed

Answer 8

Hydrogen bonds only form between hydrogen and the three most electronegative atoms:​ nitrogen, oxygen and fluorine​.

Question 9

Define electronegativity

Answer 9

The ability of an atom to attract the pair of electrons in a covalent bond

Question 10

Where are the most electronegative elements

Answer 10

Top right of the periodic table