Physics ch 12

If a neutral element has the following chemical notation, how many electrons does it have? fluorine-19

9

What is the approximate mass of a carbon atom in atomic mass units, how about a carbon dioxide molecule?

A carbon atom has a mass of about 12 amu. Carbon dioxide would have a mass of 44 amu

What is the main difference between a conceptual model and a physical model?

A physical model represents the shape and form while a conceptual model describes how a system behaves.

If you remove 2 neutrons and 2 electrons from a silver atom, what new element is formed?

Ag+2

What does the element description ____-57 mean?

An atom with a mass number of 57

Evidence for the existence of neutrons did not come until many years after the discoveries of the electron and the proton. Give a possible explanation.

The neutron lacks an electrical charge.

What are metalloids?

elements that have some properties like metals and some like nonmetals

Which of these does not describe a metal at room temperature?

gas

What vibrates within an atom as it emits electromagnetic waves?

The electron

Which of the following elements is a transition metal?

Copper, iron, nickel, cobalt, gold, zinc, chromium, manganese, titanium, mercury, silver, platinum,

Rank the following by relative frequency from highest to lowest

Cosmic rays, blue light, red might, radio waves

Light is emitted as an electron transitions from a higher energy orbital to a lower energy orbital. How long does the actual transition take?

No time at all

How can a hydrogen atom, which has only one electron, have so many spectral lines?

One electron can be boosted to many different energy levels.

Why are the atomic masses listed in the periodic table not whole numbers?

The atomic masses are average atomic masses