Behavior of Water
What property of water causes water molecules to stick to one another?
What is cohesion
I have the chemical symbol O and am essential for breathing. What element am I?
What is Oxygen
What happens to atoms during a chemical reaction?
What is they are rearranged but not lost or created
A _____________ is a state of matter with a rigid , a definite shape, and a definite _____________.
What is a solid and structure
What should you do when the teacher or another student is speaking to the class?
Listen respectfully, avoid interrupting, and pay attention to the speaker.
Why does water form rounded droplets on some surfaces?
Cohesion between water molecules creates surface tension, causing the water to pull together and form droplets.
I have the chemical symbol Na, an atomic number of 11, and I combine with chlorine to form table salt. What element am I?
What is sodium?
In the equation 2H₂ + O₂ → 2H₂O, what are the reactants and what is the product?
The reactants are hydrogen (H₂) and oxygen (O₂). The product is water (H₂O).
An ______________ is the basic unit of matter that cannot be broken down further by chemical means.
What is an atom
Why is it important to follow classroom procedures even when the teacher is helping another student?
Procedures help the classroom remain safe, organized, and productive and allow everyone to continue learning.
A paper towel is placed partially in a cup of colored water. After several minutes, the water moves upward through the paper towel. What property of water helps explain this?
Capillary action, which results from adhesion between water and the paper towel fibers along with cohesion between water molecules.
I am a metal with the chemical symbol Fe. I am commonly used in construction and can react with oxygen and water to form rust. What element am I?
What is Iron
Count the number of oxygen atoms on each side of this equation: 2CO + O₂ → 2CO₂. Does the number of oxygen atoms remain the same?
Yes. There are 4 oxygen atoms on the reactant side and 4 oxygen atoms on the product side.
A student says saltwater is a pure substance because it looks the same throughout. Do you agree? Explain.
No. Saltwater is a homogeneous mixture. It looks uniform, but it contains at least two substances—salt and water—that are physically combined.
Your group members are talking about something unrelated during a science activity. What is the most responsible action you could take?
Respectfully remind the group of the assignment and help everyone get back on task.
A student places drops of water on wax paper and a paper towel. The water beads up on the wax paper but spreads through the paper towel. Explain why the water behaves differently.
Water has little attraction to the wax, so cohesion causes it to form droplets. Water is attracted to the paper towel fibers, so adhesion and capillary action cause it to spread through the towel.
My atomic number is 6, which means I have 6 protons. I am a nonmetal and an important element in all known living organisms. What element am I, and how could you use the periodic table to verify your answer?
Carbon. The periodic table shows that carbon has the symbol C and atomic number 6, confirming that a carbon atom has 6 protons.
A student writes H₂ + O₂ → H₂O and claims the equation follows the law of conservation of mass. Is the student correct? Explain.
No. There are 2 oxygen atoms on the reactant side but only 1 oxygen atom on the product side. The equation must be balanced: 2H₂ + O₂ → 2H₂O.
Why is water classified as a compound rather than an element or mixture?
It is made up of two or more different elements that are chemically bonded together.
A student finishes an assignment early and begins distracting classmates who are still working. What would have been a better choice, and why?
The student should complete an approved activity, review their work, read, or quietly wait for further instructions. This respects other students' opportunity to learn.
A plant's roots absorb water from the soil, and the water travels upward through narrow tubes in the plant. Explain how cohesion, adhesion, and capillary action work together to help move the water.
Adhesion causes water molecules to stick to the walls of the plant's tubes, while cohesion causes water molecules to stick to each other. Together, these properties contribute to capillary action, helping water move upward through the narrow tubes.
An unknown element has an atomic number of 14. It is located along the staircase line on the periodic table and has properties of both metals and nonmetals. Identify the element and classify it as a metal, nonmetal, or metalloid. Explain your reasoning.
Silicon (Si). Silicon has an atomic number of 14 and is classified as a metalloid because it has properties of both metals and nonmetals and is located along the staircase region of the periodic table.
During a chemical reaction, a student observes that the products have completely different properties from the reactants. The student concludes that some of the original atoms must have disappeared and new atoms were created. Evaluate this conclusion using the law of conservation of mass.
The conclusion is incorrect. The atoms did not disappear or become newly created. The original atoms were rearranged and bonded in different ways, producing new substances with different properties while conserving the number of each type of atom.
Suppose you are given a substance containing only one type of atom. How would you classify it? Defend your answer.
It is an element because elements consist of only one type of atom.
Your group disagrees about how to complete a classroom activity, and everyone believes their idea is best. How could your group solve the disagreement while demonstrating leadership and respect?
Each person should have an opportunity to explain their idea. The group should listen respectfully, discuss the strengths of each option, and reach a fair decision based on the assignment requirements.