Ch. 2 Presentation

Multiple Choice

What happens when carbon dioxide (CO2) dissolves in water?

• It forms an acid, making the water more acidic.

• It turns into oxygen.

• It evaporates immediately.

• It becomes solid.

Open Ended

Why is water considered essential for life on Earth?

Multiple Choice

Which of the following statements about chemical elements and compounds is correct?

• A compound consists of two or more different elements in a fixed ratio.

• All elements are compounds.

• Compounds are made up of only one type of atom.

• Elements cannot combine to form compounds.

Open Ended

What is a compound, and how does it differ from an element?

Multiple Select

Which of the following are considered trace elements in the human body?

• Magnesium, Sulfur, Sodium, Chlorine

• Oxygen, Carbon, Hydrogen, Nitrogen

• Calcium, Phosphorus, Potassium, Sulfur

• Magnesium, Trace elements (<0.01%), Sodium, Chlorine

Multiple Choice

Which four elements make up about 96% of the weight of most living organisms?

• Oxygen, Carbon, Hydrogen, Nitrogen

• Oxygen, Carbon, Calcium, Potassium

• Hydrogen, Nitrogen, Sodium, Chlorine

• Carbon, Sulfur, Phosphorus, Magnesium

Open Ended

Explain why trace elements are important for human health, providing at least one example from food or water additives.

Fill in the Blanks

A serving of cereal fortified to provide 100% of the recommended daily intake contains 18 mg of iron. The recommended tolerable upper intake level is 45 mg (before causing gastrointestinal upset). How many bowls of cereal can you eat before you exceed that level?

Multiple Choice

Which subatomic particles are found in the nucleus of an atom?

• Protons and neutrons

• Electrons and protons

• Neutrons and electrons

• Only protons

Open Ended

A nitrogen atom has 7 protons, and its most common isotope has 7 neutrons. A radioactive isotope of nitrogen has 9 neutrons. What is the atomic number and mass number of this radioactive nitrogen?

Fill in the Blanks

The atomic number of carbon is

.

Multiple Choice

Which of the following statements about isotopes is/are correct?

• Isotopes have the same number of protons but different numbers of neutrons.

• Isotopes have different atomic numbers.

• Isotopes have the same mass number.

• Isotopes have different numbers of electrons.

Open Ended

Why are radioactive isotopes useful as tracers in research on the chemistry of life?

Multiple Choice

Which of the following is a practical use of radioactive isotopes in medicine, as shown in the images?

• Imaging organs in the body

• Treating bacterial infections

• Measuring blood pressure

• Curing viral diseases

Multiple Choice

What is the main difference observed between the brain scans of a healthy person and an Alzheimer's patient?

• The Alzheimer's patient has more brain activity overall.

• The healthy person has more brain activity overall.

• Both have the same level of brain activity.

• The Alzheimer's patient has a larger brain.

Open Ended

Looking at the electron distribution diagrams for hydrogen, oxygen, nitrogen, and carbon, how many covalent bonds can each form?

Open Ended

How does the distribution of electrons in an atom determine its chemical properties?

Multiple Select

Select all elements from the periodic table shown that have a full outer electron shell.

• Helium

• Neon

• Argon

• Fluorine

Multiple Choice

Which of the following atoms has five electrons in its outer shell based on the electron shell diagram?

• Boron

• Nitrogen

• Oxygen

• Carbon

Fill in the Blanks

The element with

electrons in its outer shell is carbon.

Open Ended

Explain why the bonds in a water molecule are polar covalent bonds.

Multiple Choice

What happens to the electrons when two hydrogen atoms form a covalent bond?

• They are shared between the atoms

• They are transferred to one atom

• They are lost from both atoms

• They remain unpaired

Fill in the Blanks

The molecular formula for methane is

.

Open Ended

Explain what holds together the ions in a crystal of table salt

Draw

Fill in the blanks

Multiple Choice

After a hard workout, you may notice “beads” of sweat on your face. Can you explain what holds the sweat in droplet form on your face?

• Heat causes the sweat to disappear.
• cohesion holds the sweat in droplet form

• Humidity causes sweat to bead up.

• Gravity pulls the sweat to each other.

Open Ended

Reflecting on what you learned about the chemical basis of life, what questions do you still have or what would you like to know more about regarding the role of water in living organisms?

Multiple Choice

How does carbon dioxide (CO2) in the air contribute to making water more acidic, and why is this important for coral reefs?

• CO2 reacts with water to form an acid, increasing water acidity, which can harm coral reefs.

• CO2 cools the water, making it less acidic, which helps coral reefs.

• CO2 is absorbed by coral reefs directly, making them stronger.

• CO2 has no effect on water or coral reefs.