Atomic Theory and EM Spectrum
Quantum Mechanical Model and Electron Configurations
Periodic Table
Nuclear (Alpha, Beta Decay and Gamma Radiation.
Sig Figs
100
What are the three main subatomic particles in an atom, and where is each one located?
The three main subatomic particles are protons (located in the nucleus and positively charged), neutrons (located in the nucleus with no charge), and electrons (located outside the nucleus and negatively charged).
100
What does the Quantum Mechanical Model say about where electrons are likely to be found in an atom?
The Quantum Mechanical Model says we can’t know exactly where an electron is, only where it’s most likely to be found.
100
What information can you find on a typical square of the periodic table for an element?
A box on the periodic table usually shows the element’s name, symbol, atomic number, and atomic mass.
100
What is nuclear radiation, and where does it come from in an atom?
Nuclear radiation is energy or particles released from the nucleus of an atom when it’s unstable.
100
What are significant figures, and why are they important in science?
Significant figures are the digits in a number that actually count, and they’re important because they show how precise a measurement is.
200
How did Dalton's atomic theory explain matter, and what was one limitation of his model?
Dalton said everything is made of tiny atoms and that atoms of the same element are the same, but his model wasn’t perfect because atoms actually have smaller parts.
200
What is an orbital, and how is it different from a simple circular path around the nucleus?
An orbital is a region where an electron is likely to be, not a neat circular path like in older atom models.
200
What is the difference between a group (family) and a period on the periodic table?
A group goes up and down and has elements with similar properties, while a period goes left to right across the table.
200
What particle is released during alpha decay, and how does it affect the nucleus of the atom?
In alpha decay, the atom gives off an alpha particle (2 protons and 2 neutrons), which makes the nucleus smaller and changes it into a different element.
200
How many significant figures are in the number 0.0450?
0.0450 has 3 significant figures (the zero at the end counts because it’s after the decimal).
300
How did Thomson’s cathode ray experiment change scientists’ understanding of atomic structure?
Thomson’s experiment showed that atoms have electrons, which proved atoms aren’t solid and indivisible like people once thought.
300
What do the letters s, p, d, and f represent in electron configurations?
The letters s, p, d, and f are different types of orbitals that have different shapes and energy levels.
300
How does atomic size generally change as you move across a period and down a group?
Atomic size gets smaller across a period and bigger as you go down a group.
300
What happens to an atom during beta decay, and what type of particle is released?
In beta decay, a neutron turns into a proton and releases a beta particle (an electron), which changes the element but not the mass much.
300
Round 23.6789 to three significant figures.
23.6789 rounded to three sig figs is 23.7.
400
List the regions of the electromagnetic spectrum in order from lowest energy to highest energy.
The electromagnetic spectrum goes from radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, to gamma rays, in that order from lowest to highest energy.
400
Write the electron configuration for a nitrogen atom using orbital notation.
Nitrogen’s electron configuration is 1s² 2s² 2p³.
400
Why do elements in the same group often have similar chemical properties?
Elements in the same group act alike because they have the same number of valence electrons.
400
How is gamma radiation different from alpha and beta radiation in terms of mass and charge?
Gamma radiation has no mass and no charge, while alpha and beta radiation are actual particles with mass and charge.
400
Medium–Hard: When multiplying or dividing numbers, how do you decide how many significant figures the final answer should have?
When multiplying or dividing, the answer should have the same number of sig figs as the number with the fewest sig figs.
500
Explain how the behavior of electrons in atoms is related to the emission of specific wavelengths in the electromagnetic spectrum.
When electrons move between energy levels, they give off or take in energy as light, which shows up as specific wavelengths on the electromagnetic spectrum.
500
Why do electrons fill lower-energy orbitals before higher-energy ones, and how does this relate to the Quantum Mechanical Model?
Electrons fill the lowest-energy orbitals first because it takes less energy, which fits with the Quantum Mechanical Model’s idea of energy levels.
500
How can an element’s position on the periodic table help you predict its reactivity and number of valence electrons?
Where an element is on the periodic table tells you how many valence electrons it has and gives you a good idea of how reactive it will be.
500
Compare alpha, beta, and gamma radiation in terms of their penetrating power and potential danger to living tissue.
Alpha radiation is the least penetrating, beta goes farther, and gamma is the most penetrating and can be the most dangerous if you’re not protected.
500
Explain why 12.0 + 3.45 must be rounded differently than 12.0 × 3.45 when using significant figures.
For addition/subtraction, you round based on decimal places, but for multiplication/division, you round based on sig figs, so the rules are different.