C2 Questions Flashcards
The plum pudding model suggests that most of the atom is…
The plum pudding model suggests that most of the atom is positive ‘dough’. The plum pudding model was introduced to explain the two types of charge; positive and negative.
What was the surname of the scientist who suggested the plum pudding model?
J J Thomson suggested the Plum pudding model in 1897.
What did Ernest Rutherford direct at a thin gold leaf in 1905?
Alpha particles were scattered from a gold foil in this famous experiment.
Most alpha particles going straight through the gold foil tells us that …
The atom is mostly space and most of the alpha particles miss the nucleus completely.
What did Niels Bohr add to the Rutherford Atomic model?
Niels Bohr added electron orbits to the Rutherford model. The conclusion from Rutherford’s experiment was that the nucleus existed.
The Rutherford scattering experiment proved the existence of what?
The Rutherford scattering experiment proved the existence of the nucleus. No one scientist has ever been credited for discovering the proton.
Who discovered the neutron?
James Chadwick discovered the neutron in 1932.
Why did Rutherford use gold foil in his experiment?
Gold can be made very thin so that the alpha particles can get through it.
In the current model of the atom, what are the two particles that are present in the nucleus?
Protons and neutrons are found in the nucleus, electrons orbit the nucleus.
How many times bigger is the atom compared to the nucleus?
The atom is at least 10,000 times bigger than the size of the nucleus.
How many neutrons does 146C contain?
Number of neutrons = mass number - atomic number = 14 - 6 = 8 neutrons.
What is the relative mass of the proton?
Protons (and neutrons) have a relative mass of 1. Electrons have a mass of 1/2,000 that of a proton and are often thought of as having no relative mass.
What is the relative charge of a neutron?
The relative charge of a neutron is 0. Neutrons are neutral and have no charge
What is an isotope?
A nucleus with the same number of protons but different number of neutrons is called an isotope.
Uranium-235 has 92 protons. How many neutrons does it have?
Uranium-235 has 143 neutrons. 92 is the number of protons.
Nitrogen-14 has 7 protons. How many neutrons does it have?
Nitrogen-14 has 7 neutrons. Mass number - proton number = number of neutrons. 14 - 7 = 7.
The mass number of an element is …
The mass number of an element is the number of protons and neutrons. Sometimes also called the nucleon number
The atomic number of an element is …
The number of protons is called the atomic number. Atoms of the same element may have different numbers of neutrons.
What has an ionised atom lost or gained?
An ionised atom has lost or gained electrons. An ion is an atom that has lost or gained electrons.
What has changed in the structure of the Cu2+ ion?
It has lost two electrons. If it has gained two electrons it would be a 2- ion as electrons are negatively charged.
Why is deuterium 2,1 H
sometimes called heavy hydrogen?
It has an extra neutron. An extra proton would make it helium.
True or false, The vertical columns are called periods.
False
Elements in the same period:
Elements in the same period have the same number of electron shells.
True or false, Elements in Group 7 become more reactive as you move up the group is the true statement.
True
Elements in the transition element block of the periodic table:
Elements in the transition element block of the periodic table have ions of the same element with different charges.
Which of the following reactions actually occurs as written?
The reaction: Cl2 + 2NaI → 2NaCl + I2 actually occurs as written.
Which statement correctly describes the changes Mendeleev made in the development of the periodic table?
The correct statement is: He arranged the elements in order of atomic weight, swapped some elements so that elements in the same group had similar properties and left gaps for undiscovered elements.
Which of the following equations represents the balanced symbol equation for the reaction of potassium with water?
The correct answer is 2K + 2H2O → 2KOH + H2
True or False, Elements increase in reactivity across the periodic table.
False
The half equation for the formation of potassium ion from a potassium atom is represented as:
The half equation for the formation of potassium ion from a potassium atom is represented as K → K+ +e-
The half equation for the formation of chloride ions from a chlorine molecule is represented as:
The half equation for the formation of chloride ions from a chlorine molecule is represented as Cl2 + 2e- → 2Cl-
Write the word equation and balanced equation for the reaction of potassium with water.
potassium + water → potassium hydroxide + hydrogen
2K(s) + 2H2O(l) → 2KOH(aq) + H2(g)
The table above shows the melting points of five alkali metals. Use this information to describe how melting point changes in group 1.
Going down group 1, the melting point decreases.
Use the information in the table to predict the melting point of francium, Fr. Explain your answer.
The melting point of francium will be around 27°C. This is because francium is below caesium in the periodic table, so it should have a lower melting point, and the difference in melting point decreases going down from one element to the next.
