Sub script · Thursday, Jan 1 · for Sample Teacher · grade 7-10
The whole day, 8:05–8:55
Thank you for being here. Everything today runs from this page and the students' screens; you do not need to know any chemistry, and you do not need to teach anything.
Write on the board
Website: coveredclass.com/go
- Period 2: DEM-O01
Emergency folder (roster, paper packets): Top drawer, left of the desk
| Time | Block |
|---|---|
| 8:05–8:55 | Period 2 — Intro Chemistry · code DEM-O01 |
Period 2 — Intro Chemistry (8:05–8:55, 50 min · code DEM-O01)
Why Does Ice Float?
| Clock | Min | What to do and say |
|---|---|---|
| 8:05 | 5 | Take attendance using the roster in the emergency folder. Write the class code from the top of this page on the board, large. Tell students: "Open a Chromebook, go to the website on the board, type the code, your first name, and last initial." Anyone without a device gets a paper packet from the folder. |
| 8:10 | 4 | Say: "Read the first section, called The Hook, silently. Then I'll read it out loud once." Read the Hook paragraph aloud from your printout at a normal pace. Do not explain it. If someone asks a question, say: "Hold that thought; the next section answers most questions." |
| 8:14 | 8 | Say: "Now read the Mini-Lesson on your own. It is five short paragraphs. When you finish, start the activity underneath it." Walk the room. Your only job is to keep screens on the lesson page. If a student says they are done in under three minutes, say: "Read it again and underline the word density each time it appears." |
| 8:22 | 20 | Students do the drawing activity and type answers to the four prompts. Say once: "You need two drawings on paper and four typed answers. Complete sentences." Circulate. It is fine for students to talk quietly about the drawings. If someone asks a science question, say: "Check paragraph three or four in the Mini-Lesson; the answer is there." Give a two-minute warning. |
| 8:42 | 10 | Say: "Stop typing on the activity. Scroll down to the Exit Ticket. Five questions. Answer them on your own, then press Submit at the bottom." Students should see a score for the multiple-choice questions after submitting. Do not read questions aloud or give hints. Anyone on paper fills in the exit ticket on the last page of the packet. |
| 8:52 | 3 | Say: "If you haven't pressed Submit, do it now. Drawings go in the tray on the teacher's desk with your name on them. Close your Chromebook and put it back in the cart." Collect any paper packets. Before you leave, type a short note to the teacher at the bottom of this page: who was absent, what went well, anything odd. |
The hook (read this aloud)
Here's something you've seen a thousand times and probably never questioned. Drop an ice cube in a glass of water. It floats. But almost every other substance sinks when it freezes. The solid is denser than the liquid. Water breaks that rule. When it freezes, water expands. The ice ends up about nine percent less dense than the liquid it came from. That happens because of how water molecules grab onto each other. As they slow down and lock into place, they form a wide, open, hexagonal pattern. Lots of empty space. That empty space is why lakes freeze from the top down instead of the bottom up. It's why fish survive the winter.
Exit ticket answers (for paper packets; online is scored automatically)
- Density is best described as: — B. How much mass is packed into a certain amount of space
- Compared to liquid water, ice is: — C. About 9 percent less dense
- What holds water molecules in an open hexagonal pattern when they freeze? — A. Hydrogen bonds between neighboring molecules
- Why do lakes freeze from the top down? — B. Ice is less dense than liquid water, so it stays at the surface
- In one sentence: what is the shape of the pattern water molecules form when they freeze, and why does that shape make ice float? — Water molecules lock into a hexagonal (six-sided) pattern with empty space inside each ring, so ice is less dense than liquid water and floats.
If the wifi is down: Hand out the paper packets from the emergency folder (or the stack on the teacher's desk). The packet has the same hook, mini-lesson, activity, and exit ticket. Students write on the packet. Collect every packet at the end and leave the stack on the teacher's desk. Read the Hook aloud exactly as you would if the screens worked; the timing on this page does not change.
Please do not
- Do not run any demonstration with water, ice, or a freezer; this is a reading and writing lesson only.
- Do not let students leave to get a Chromebook from another room; use paper packets instead.
- Do not show videos or search the internet for extra material; everything needed is on the page.
- Do not grade or comment on student answers; the teacher will see the results this afternoon.
If a student asks a content question
Say: “Write it down for your teacher.” You do not need to know the subject.