ATOMIC STRUCTURE
An atom contains 12 protons. Which element is it?
Magnesium
An atom has 11 protons and 11 electrons. What is its overall charge?
Neutral
An isotope contains 9 protons and 10 neutrons. What is its mass number?
19
How many electrons can the p sublevel hold?
6
If the wavelength of light becomes shorter, what happens to its frequency?
Frequency increases.
Which subatomic particle is found outside the nucleus?
Electron
An atom has 17 protons and 18 electrons. What is its charge?
-1.
Two isotopes have masses of 10 amu and 11 amu. If the 10-amu isotope is much more abundant, will the average atomic mass be closer to 10 or 11?
10 amu
electron configuration?
1s² 2s² 2p⁶ 3s¹
Sodium
Which has greater energy: a photon with high frequency or one with low frequency?
High frequency
Two atoms of the same element have different numbers of neutrons. What do we call these atoms?
Isotopes.
An ion contains 20 protons and 18 electrons. Is it positive or negative?
Positive
An element has two isotopes:
50.4 amu
Which element has this configuration?
[Ne] 3s² 3p³
Phosphorus
An electron moves from energy level 2 → 5. Does the atom absorb or release energy?
Absorb energy
If an atom has an atomic number of 15, how many protons does it contain?
15
An ion has 8 protons, 10 electrons, and 8 neutrons. Give its:
Oxygen, 2−, mass number 16
An element has isotopes of 64 amu and 66 amu. Its average atomic mass is 64.8 amu. Which isotope is more abundant?
The 64 amu isotope
An element has the configuration:
[Ar] 4s² 3d¹⁰ 4p²
Germanium
An electron falls from energy level 5 → 2. What happens?
It releases a photon.
A scientist observes that nearly all alpha particles pass through a thin metal foil, while a very small number bounce back. What does this suggest about the atom?
The atom is mostly empty space with a small, dense nucleus.
A particle has a mass number of 31 and an atomic number of 15. It has a -3 charge. What are the protons nuetrons, and electrons of the element.
15 protons, 16 neutrons, 18 electrons
An element has three isotopes:
31.1 amu
Which element has an outermost electron filling the 5p sublevel?
A. Sr
B. In
C. Xe
D. Zr
C. Xe — Xenon
Two unknown gases produce emission spectra. Gas X has exactly the same spectral-line pattern as a known sample of helium. What can you conclude?
Gas X contains helium, because an element's emission spectrum is characteristic of that element.