Quiz 1.1

Which of the four forces holds atoms together?

The electromagnetic force

The outer planets of our Solar System, in order of distance from the Sun are :

Jupiter, Saturn, Uranus, and Neptune

The electron is a fundamental particle: true or false?

True: it is a fundamental particle, they are made of quarks

An atom has the same number of electrons as protons. True or false?

True: the number of electrons must equal the number of protons for overall electrical neutrality; this number is called the “atomic number” , which defines an element

Elements in the same vertical group of the periodic table usually have the same valency: true or false?

True: because they all have the same number of electrons in their outer shell, which determines how many bonds they can form

The neutrino is

A lepton (light particle) similar to the electron only neutral and with an even smaller mass

Chlorine is in group VII of the periodic table. How many bonds can it form?

One: because it’s in group VII, it has 7 electrons in its outer shell and needs only one more to complete its octet

The problem with String Theory is that

The properties of all the elementary particles and forces are determined by vibrations of strings within the Calabi-Yau shape of the compactified extra dimensions and unfortunately there are 10^500 possible Calabi-Yau shapes, and there is no way of knowing which one is the one that describes our universe

The decay of radioactive uranium (238 U) into lead (206 Pb) is used to date two rocks. In sample A there is a larger amount of 238 U relative to 206 Pb. In sample B, there is a smaller amount of 238U relative to 206Pb. Which rock is older?

Sample B

The most common chemical element in the universe is

Hydrogen

The first generation of fundamental particles is

u d e- ve

The water molecule is

Bent: the oxygen atom has four electron pairs, which try to get as far apart from one another as possible, so they point to the corners of a tetrahedron resulting in the two bonds being at an angle to each other producing “bent” water molecule

The distance from our solar system to the nearest stars is

A few light years

The radioactive half-time of an element is

The time it takes for half the atoms in a sample to decay to another element

The distance to the Andromeda galaxy is

2 million light years

The nearest galaxy to ours,Andromeda is at a distance of

2 million light years

After two half-lives of radioactive element only one quarter of the original amount will be left: true or false?

True

The proton, neutron and their more exotic relatives made in particle accelerators are al

Clusters of three quarks

What is the difference between 12C bf 13 C?

12C has 6 protons and 6 neutrons while 13C has an extra neutron making 6 protons and 7 neutrons

The second generation of fundamental particles is

c s m- vm