An early model of the periodic table sorted elements by a. atomic number b. atomic weight c. number of subatomic particles
The first subatomic particle to be discovered was a. the electron b. the proton c. the neutron
A proton has a. a positive charge b. a negative charge c. no charge
Discussion/essay questions
Even though scientists did not yet understand subatomic particles, the early model that put elements in order of atomic weight still naturally grouped similar atoms together. Why do you think this is? Do you know any other historical examples of humans finding patterns that they didn’t understand?
Transcript
The periodic table is a system that scientists use to organize and classify chemical elements. Originally, many scientists tried to sort the elements by properties. One of the early models of the periodic table arranged elements by atomic weight, which naturally grouped elements with similar properties together. However, certain elements were outliers, and did not fit in their groups. In 1898, a scientist named J.J. Thomson discovered the electron, a subatomic particle with a negative charge. Later, in 1911, a scientist named Ernest Rutherford learned that electrons orbit a nucleus, which makes up most of the atom’s mass. Inside the nucleus, there are protons, which have a positive charge. An atom has an equal number of electrons and protons. This number became known as an element’s atomic number. Today, elements on the periodic table are arranged by atomic number, which gives a more accurate understanding of element properties.
The cells that make neurotransmitters are a. nerve cells b. blood cells c. skin cells
There are at least a. 100 known neurotransmitters b. 200 known neurotransmitters c. 1000 known neurotransmitters
Serotonin is responsible for a. regulating emotions b. responding to rewards c. responding to danger
Discussion/essay questions
Brain chemistry is something scientists are continuing to learn more about. Why is it important to understand the brain?
Transcript
Neurotransmitters are chemicals that nerve cells use to communicate with other parts of the body. When a nerve cell releases a chemical, it is detected by a receptor in a different cell. This gives the body a signal to do something. Some neurotransmitters control functions like moving or breathing. Others control emotions and learning processes. There are over 100 known types of neurotransmitters, all with different purposes. An imbalance of neurotransmitters can cause both mental and physical illnesses. For example, people who struggle with depression may have low levels of the chemical called serotonin, which helps to regulate emotions. Other commonly known neurotransmitters include dopamine, which responds to rewards, and adrenaline, which responds to danger.
While Marie Curie’s research did help scientists develop cancer treatments, her research was also important for the invention of the atomic bomb during World War II. The atomic bomb is still a controversial subject because of the amount of deaths it caused. Do you think Curie’s discoveries had a positive impact on the world, or a negative one?
Transcript
Marie Curie was a Polish-born French physicist, known for her research of radioactive chemicals. She was born in Warsaw, Poland in 1867, the youngest of five children in her family. Growing up, Curie was smart and curious, and dreamed of getting a university degree. However, the University of Warsaw only admitted male students at the time. In order to get her degree, Curie moved to Paris. She studied physics at Sorbonne University, and later received another degree in math. After her education, Curie went on to become a scientist. While working with a mineral known as pitchblende, Curie discovered a new chemical property, which we now know as radioactivity. She also discovered two new elements, which she called polonium and radium. Because of these scientific discoveries, Curie became the first person to ever win two Nobel Prizes. Curie died in 1934 from an illness caused by her exposure to radiation. However, her research has helped modern scientists develop treatments for cancer, and she is still seen as one of the greatest scientists of all time.
