Chemistry
What happens to atomic radius from left to right across the periodic table?
It decreases because the increasing nuclear charge pulls the electrons closer.
What are bioaccumulation and biomagnification?
Bioaccumulation - toxic chemicals being built up in a single organism
Biomagnification - the concentration of that chemical increasing going up trophic levels
Apex predators need to eat a lot of prey that can be contaminated with these chemicals, meaning they will invest a lot and be severely affected
What is the difference between the way and ammeter and a voltmeter is attached to a circuit?
An ammeter is connected in series, a voltmeter is connected in parallel.
Is the moon luminous?
The moon is a non-luminous body within our solar system because it reflects the sun’s light, not its own.
What leads to a total lunar eclipse?
The Earth being directly between the Sun and the moon, causing the moon to be in Earth’s shadow.
(A solar eclipse is when the moon is between the Sun and the Earth, causing part of the Earth to be in the Moon’s shadow)
What is the difference between ionic bonds and molecular/covalent bonds?
Ionic bonds are between non-metals and metals, transfer electrons to become stable and neutral, and have higher melting/boiling points and conductivity when dissolved or melted.
Molecular/covalent bonds are between two non-metals, share electrons to become stable and neutral, have lower melting/boiling points and do not conduct electricity.
Photosynthesis and cellular respiration
Photosynthesis: water + co2 = oxygen gas + glucose
Cellular respiration: Glucose + oxygen gas = co2 + water
Plants take in water and co2 to make glycols and oxygen, then also make water and co2 from that, causing it to be a constant cycle.
What are key characteristics of a parallel circuit?
Current divides based on the resistance of each branch, and voltage is the same across every branch.
What evidence allowed Galileo Galilei to disprove the historical geometric model of our solar system?
The full progression of orbital phases by Venus. He discovered the planet orbits the Sun and not the Earth as initially thought.
Why is deep-space ionizing radiation a hazard to astronauts?
It mutates cellular DNA and can lead to radiation sickness and cancer.
What were Bohr and Rutherford’s role in the planetary model and why is it referred to as a Bohr-Rutherford diagram?
Rutherford discovered there is a solid nucleus in the center of an element because a particle hit the nucleus and bounced back, and when passing through it came out in a different direction due to the gravitational pull of the nucleus.
Bohr discovered the orbitals inside of an atom, stating that electrons travel in specific fixed energy around a center nucleus.
What are the 4 main ABIOTIC limiting factors?
Temperature, water, sunlight and soil
Explain charging by conduction
A charged object is brought near a neutral object. Say for example the charged object has a positive charge— the electrons in the neutral object will be attracted to the positive object, and the protons in the neutral object will repel.
The negative charges and positive charges are now on separate sides. The neutral object gains the opposite charge of the charged object.
Scale of the universe
Planet < Solar system < Galaxy < Universe
What are the benefits of space spin-off engineering and provide an example?
Spinoff has profiled technologies that benefit from NASA investment and expertise. These developments have transformed into things we use in daily life, and they are often more sustainable options than what came before them. Examples are phone cameras, memory foam, and advanced water purification.
What happens to the reactivity of elements moving down group 1 as compared to moving down group 17?
Alkali metals increase in reactivity down the group, because they react by losing a single valence electron. As more shells are added, the electron becomes farther from the nucleus and therefore easier to lose.
Halogens decrease in reactivity because they react by gaining one valence electron. As more shells are added, the valence shell becomes farther from the nucleus and therefore farther from the nucleus’s attraction which attracts the extra electron.
Which cell structure is primarily responsible for performing cellular respiration? And which for photosynthesis?
Mitochondrion
Chloroplast with chlorophyll
How does an electroscope work?
An electroscope is an object with two separated metal leaves and a sphere on the top.
When a charged object charges the electroscope, the excess electrons or protons will go down into the leaves. Due to the laws of attraction, the protons will repel each other and therefore the leaves with separate.
What mechanism is responsible for producing the Sun’s electromagnetic energy? Explain the mechanism.
Nuclear fusion transforming hydrogen into helium. Hydrogen is compressed under intense pressure and heat, fusing to form the heavier element of helium. The resulting nucleus will weigh slightly less than the sum of the original two and will require less energy to hold it together, so the remaining energy is released.
What is the difference between a refracting telescope and a reflecting telescope?
A reflecting telescope collects light by means of a (usually) concave mirror.
A refracting telescope collects light by means of a lens or system of lenses.
Mirrors don't cause chromatic aberration and they are easier and cheaper to build large.
What will happen if one bulb breaks in a parallel vs in series?
If the bulbs are in parallel, the other bulbs will stay on because they are in separate branches. In series, the other bulbs will go out because the path will be disconnected.
What scientific distance metric measures the average distance between the center of the Sun and center of the Earth?
Astronomical Unit (AU)
What is the difference between the cycle of a high-mass star and a low-mass star?
A high-mass star dies quicker than, burning up hydrogen quickly. After a high-mass star’s red giant phase, it will undergo a supernova explosion. If the remnant of the explosion is 1.4 to 3 times as large as the Sun it will become a neutron star. The core will then be swallowed by its own gravity and it will become a black hole.
A low-mass star has a much longer life-span. After its red giant phase and the helium fusing into carbon, the core will collapse and the outer layers of the star are expelled. The outer layers form a planetary nebula, and becomes awhite dwarf and eventually cools to become a black dwarf.