In the following diagram, what does the number 12 represent?

He discovered the neutron in the nucleus completed the current atomic model.

he found atoms have smaller parts and found negative electrons that he theorized were surrounded in a sphere of postive charges

He found postively charged protons in the nucleus and said that electrons moved around the nucleus

He found that electrons he specific amounts of energy and move in specific orbits around the nucleus, like planets orbiting the sun

no charge

postive charge

negative charge

found in nucleus

atomic mass

atoms of the same element must always have the same number of _______

The mass number of an element that has 18 protons, 18 electrons, and 19 neutrons is ______

The atomic number of an element that has 9 protons, 9 electrons, and 10 nuetrons is____.

Democritus called the tiniest particles of matter "atomos", which is Greek for ______

An atom has an atomic number of 15 and a mass of 31. How many protons are there in the atom?

describe an Electron cloud

what might happen if the strong force didnt exist

which philosphere stated that matter was made of four elements:earth,wind,water,fire?

julie is baking a cake. the pan she is useing had a density of 6 g/ml and a volume of 42ml. what will the mass of the cake be?