If a nucleus of carbon (6 protons, 6 neutrons) underwent nuclear fusion with a nucleus of helium (2 protons, 2 neutrons), what would likely happen?

When thinking about the cosmos, it is easy to be overwhelmed by its immense scale. Let’s start by putting everything into context according to scale. Order the following terms, starting with the largest and progressing to the smallest.

The anthropogenic changes that the Earth experiences are directly tied to pressures applied by the growing human population. Take a look at the graph below. Based on the graph, what was the approximate human population in 2018?

Astronomers use spectral classes to categorize stars based on their surface temperature. What class star is the Sun?

Using the three scales again, classify a class M star, like Betelgeuse.

Changes can be considered as being naturally occurring or anthropogenic—that is, resulting from human activity. Which of the following changes are anthropogenic?  

[Climate Change While we can physically measure the current levels of carbon dioxide, to estimate future concentrations, we have to employ computer models. On the graph below, we can see the marked increase in CO2 since the industrial revolution. This includes the observed CO2 concentration for 2018 and two predictive points based on a low-emissions and high-emissions model. If you were creating a model to estimate future CO2 concentrations, which of the following would you consider?

Differentiation led to the Earth separating into layers based on density. Drag the layer labels to the correct locations on the triangular schematic of Earth’s interior below.

Another anthropogenic change the Earth experiences is pollution. Match the type of pollution with the anthropogenic cause.  

Real-world systems are often complex and are where natural and anthropogenic influences interact. The carbon cycle is one such system. There are processes, both human-made and natural, that release carbon into the atmosphere. There are processes in which carbon is absorbed from the atmosphere. On the image below, select the processes that absorb carbon dioxide from the atmosphere.