Chemistry of matter: atoms intro · Classroom

1. Hook

How to do this lesson online

Read (or listen to) what you’re learning. Don’t jump to the quiz.
Walk the worked example. Then use the interactive lab on this page.
Guided set → independent set → mastery check → teach-back.
If you write a paper, stay on campus: Citation Helper, Source Library, Paper Studio.

This is self-paced homeschool on Life Academy. Everything you need is on this page.

Today's puzzle

Everything you've ever touched is made of about 118 kinds of building blocks. What are they, and how small are they?

Then: lab → guided → quiz → teach it back. The lab is the lesson, not a decoration.

2. Teach

What you're learning

Describe atoms and their parts and use models to explain atomic structure (NGSS MS-PS1-1).

Standards alignment: NGSS MS-PS (domain-level; works with any state’s standards)

STEM in this lesson

Atoms are tiny: a typical atom is about 10^-10 m across. Atoms have protons (+), neutrons (no charge), and electrons (−).

Hold onto these

An atom has a nucleus of protons (positive) and neutrons (neutral), surrounded by electrons (negative).
The number of protons (atomic number) identifies the element: carbon always has 6.
In a neutral atom, electrons = protons. Mass number = protons + neutrons.

This week’s lesson

Atoms are tiny: several million carbon atoms would fit across a 1-millimeter line. The nucleus is tiny even compared to the atom, but holds nearly all the mass.

Models changed with evidence: Dalton (solid spheres), Thomson (electrons discovered), Rutherford (dense nucleus from the gold-foil experiment), Bohr (electron energy levels), and today's electron cloud model.

Watch one worked example

Oxygen: atomic number 8, mass number 16.
Protons = 8.
Neutrons = 16 − 8 = 8.
Neutral atom electrons = 8.

Now you try — with me

Draw Bohr-style models of helium (2 p, 2 n) and carbon (6 p, 6 n). Label each part and its charge.

The usual mistake

Thinking the number of neutrons identifies the element (it's the number of protons).

Why this shows up in real life

Atomic structure explains everything from how batteries work to why metals conduct electricity.

No classroom teacher today — this page is the lesson. Follow the how-to, then the lab, then the quiz. Follow Lesson Studio, then the lab, then the quiz.

Interactive lab (on this page)

Change one variable. Record what happened. This model is the lab — not an off-site sim.

Play & explore

Hands-on practice for this lesson. Your progress saves automatically.

Your work — type it here

Do the lab first. Then write what you noticed. Then a because-sentence. That is the assignment.

1. Carbon's atomic number

2. Sodium: 11 protons, mass number 23: neutrons

3. Scientist of the gold-foil experiment (last name)

Lab write-up — Claim (one sentence about this week's skill). Evidence (what you saw). Because. That shape is called CER — the same honesty high school science will want.

3. Guided practice

Try these with me — type the missing word, then check.

Oxygen with mass number 16 and 8 protons: neutrons

Charge of an electron (one word)

Particle with no charge (one word)

Reveal the thinking

Atomic number = protons; neutrons = mass number − protons; electrons = protons if neutral.

4. Independent practice

Work the set. Check when finished — this is practice (mastery quiz is next).

5. Mastery check

Scored quiz — results save to your gradebook.

The lab is on this page

Do the experiment here. Change one thing. Read what happened. We do not send you to an outside simulation site. Today: Chemistry of matter: atoms intro.

Interactive lab (this page)Move the model. A fair test changes one variable.CER write-upClaim, evidence, reasoning — when this week asks you to write it up.Name the limitationWhat this test cannot prove is part of the science.

Classroom · Gradebook · Transcripts

Stay on this page. The studio, the lab, pictures, and Your work are the lesson.

6. Reflection / teach-back

Teach-back: Explain Chemistry of matter: atoms intro in your own words. Give one example and name the usual mistake.

Your teach-back