Mastering Physics unit 2 chapter 12

If two protons and two neutrons are removed from the nucleus of an oxygen-16 atom, a nucleus of which element remains?

12/6C

The nucleus of an electrically neutral iron atom contains 26 protons. How many electrons does this iron atom have?

26

Which of the following best explains what is happening when an atom emits light?

An electron is dropping from a higher to a lower energy level with the difference in energy between the two being emitted as light.

Which color of light comes from the higher energy transition, red or blue?

Blue is a higher frequency and therefore corresponds to a higher energy level transition.

Choose the most likely set of mass numbers for these two bromine isotopes.

Br−79, Br−81

Rank the three subatomic particles in order of increasing mass: (a) neutron, (b) proton, (c) electron.

C B A

Which is heavier: a water molecule, H2O, or a carbon dioxide molecule, CO2?

CO2

What is the atomic symbol for the element cobalt?

Co

What was Niels Bohr's explanation for the observation of atomic spectra?

Electrons could only move in discrete energy steps within an atom.

Rank the following elements in the order of their decreasing atomic diameter based on their effective nuclear charge.

Lithium, Boron, Nitrogen, Fluorine

A chemist classifying five elements determines the following:

Metals: Ag Hg Metalloid: Si Nonmetals: S Ne

Rank them in terms of their atomic number, from largest to smallest.

Ni, Ca, Si

Sort each of the items into the appropriate bin. Use the diagram of a neutral lithium atom, shown to the left, for reference.(Figure 1)

Proton: particle labeled "B" +1 charge approximately the same mass as a neutron Neutron: particle labeled "A" no charge Electron: particle labeled "C" -1 charge smallest mass of the three particles

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

The atomic masses are average atomic masses.

A cat strolls across your backyard. An hour later, a dog with its nose to the ground follows the trail of the cat. Explain what is going on from a molecular point of view.

The dog is smelling molecules from the cat.

Is there a limit to the number of electrons that can occupy a single shell?

Yes, because that's just the way it is

Which of the following is a property of light?

all of the above

Which has more potential energy: an electron close to an atomic nucleus or an electron far from an atomic nucleus?

an electron far from an atomic nucleus

Identify the chemical symbols corresponding to each element.

carbon: C Lead: PB Antimony: SB sodium: Na Aluminum: Al

When we use a scanning probe microscope, do we see atoms directly or only indirectly?

indirectly

Are most elements metallic or nonmetallic?

metallic

Is it possible to see an atom using visible light?

no

A unit of light is the _______.

photon

Which contributes more to an atom's mass: electrons or protons?

protons

What is at the center of every atom?

the atomic nucleus