The chart lists four different kinds of atoms. A chart titled Different Kinds of Atoms with the entries calcium, gold, argon, iodine.

What is true about all of these atoms?

They cannot be solids.
They are the largest units of matter.
They are the only types of atoms that exist.
They cannot be divided and still keep the properties of the element.

Apulley with mass mp and a radius rp is attached to the ceiling, in a gravity field of 9.81 m/s2 and rotates with no friction about its pivot.

I'm thinking it's 2 you are asked to explain the earth's magnetic field. which is the best reply? 1. the earth's magnetic south is similar to the north pole of a magnet. 2. the earth's core has a strong magnetic charge similar to the south pole of a magnet. 3. the earth's geomagnetic south is similar to the south pole of a magnet. 4. the earth's magnetic charge is not centered at either pole; it varies based on location.

Mr. polifka does a demonstration in science class. he holds an unlit match six inches above a candle flame. after a while, the match bursts into flame.