Which describes a quark?
A)one of the most basic types of particles
B)a variety of an element that has different number of neutrons
C)a particle in the nucleus that has one of the most significant amounts of mass
D)the smallest atom identified by scientists
****I think it is A, but am not completely sure, please help w/explanation!!***
A is correct although C comes close but I would discount C because quarks, as individual particles, are not present in the nucleus. Neutrons and protons are made of quarks; neutrons and protons are in the nucleus.
There are six kinds of quarks (at least the last time I counted) each with a corresponding anti-quark; up quarks and down quarks along with charm, strange, top (or truth) and bottom (or beauty) and these names may have changed by now. The up quarks have +2/3 charge and the down quarks have -1/3 charge. A proton is made of 2 ups and 1 down (2/3 + 2/3 - 1/3 = 3/3 = +1 charge) while a neutron is made of 1 up and 2 down (+2/3 - 1/3 - 1/3 = 0 charge). There is more but I think that answers the question without getting too whacky.