Topic 19 Sinks, floats, sticks to a magnet: choosing materials — what needs James (0)
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Question types (10)
One exemplar per question type in the test bank; approving a type approves every item written to it. The full type sheet.
Topic 19 · Sinks, floats, sticks to a magnet: choosing materials · Type 1 · bank item PP-1 · tests MAT3-007
EasyMCQType 1 — four objects were let go in four tanks: which one sinks (or floats — vary)
drawing tanks_pp_four
Four objects were let go in four tanks of water. Which object sinks?
- a) the raisin ← key
- b) the plastic lid
- c) the tennis ball
- d) the sponge
Why it is this type: Easy because: one drawn place read against the taught criterion. Replaces the typed raisin-and-lid item (James: an MCQ in text entry's clothing) and Rocco's table read (deleted).
The why line (what a student reads after answering): The raisin rests on the floor of its tank. / If it goes to the bottom, it sinks. / The lid, the tennis ball and the sponge stay at the top, so they float. / So the raisin sinks.
Recommendation: Approve as the exemplar
Topic 19 · Sinks, floats, sticks to a magnet: choosing materials · Type 2 · bank item PP-2 · tests MAT3-008
EasyMCQType 2 — a magnet comes close to four objects with their materials named: which one is magnetic
A magnet comes close to each of these objects. Which one is magnetic?
- a) a glass jar
- b) a cotton sock
- c) a plastic ruler
- d) a steel washer ← key
Why it is this type: Easy because: one recall of what a magnet pulls, the materials named.
The why line (what a student reads after answering): A magnet pulls steel, so steel is magnetic. / Glass, cotton and plastic are not magnetic. / So the steel washer is magnetic.
Recommendation: Approve as the exemplar
Topic 19 · Sinks, floats, sticks to a magnet: choosing materials · Type 3 · bank item PP-3 · tests MAT3-008
EasyMCQType 3 — a drawn sort into MAGNETIC / NOT MAGNETIC with one object misplaced: which object is in the wrong group
drawing sort_pp_wrong_one
Clem sorted these objects into the two groups. Which object is in the wrong group?
- a) the steel washer
- b) the steel spring ← key
- c) the cork
- d) the glass marble
Why it is this type: Easy because: each drawn object is judged once against "steel is magnetic" (re-ranked from medium on the atom-order rule).
The why line (what a student reads after answering): The steel spring sits in the not-magnetic group. / Steel is magnetic. / So the steel spring is in the wrong group.
Recommendation: Approve as the exemplar
Topic 19 · Sinks, floats, sticks to a magnet: choosing materials · Type 4 · bank item PP-4 · tests MAT3-060
MediumMCQType 4 — three blocks made and tested the same way, the three outcomes STATED: what did the test show
Tuva let three blocks of the same size fall from the same height: the cement-only block cracked, the gravel-only block rolled apart, and the cement-and-gravel block stayed whole. What did Tuva find out?
- a) Gravel alone makes the strongest block.
- b) Cement alone makes the strongest block.
- c) Cement and gravel mixed together make a stronger block than either alone. ← key
- d) Mixing made no difference.
Why it is this type: Medium because: three outcomes are held together and turned into the atom's conclusion. Replaces Tuva's table read (deleted). The key is the longest option by nature of the conclusion; the bank generator varies which option is the mix so the length never marks it.
The why line (what a student reads after answering): Cement alone cracked, and gravel alone rolled apart. / Cement and gravel mixed together stayed whole. / A block that stays whole when it falls is strong. / So the mix made a stronger block than either alone.
Recommendation: Approve as the exemplar
Topic 19 · Sinks, floats, sticks to a magnet: choosing materials · Type 5 · bank item PP-5 · tests MAT3-060
MediumMCQType 5 — three lumps of a mix tested to see which dries hardest: which ONE thing should be different
Iker tests three lumps of papier-mâché to see which mix dries hardest. Which one thing should be different between the lumps?
- a) how big they are
- b) how long they dry
- c) what they are made of ← key
- d) how far they fall
Why it is this type: Medium because: the fair-test rule is applied to a fresh make-and-test.
The why line (what a student reads after answering): Iker wants to know which mix dries hardest. / So what the lumps are made of is the one thing that changes. / Size, drying time and the height of the fall stay the same: a fair test.
Recommendation: Approve as the exemplar
Topic 19 · Sinks, floats, sticks to a magnet: choosing materials · Type 7 · bank item PP-6 · tests MAT3-061
MediumMCQType 7 — a material suits a job (verdict in the stem): which property makes it suit
Rubber suits the handle grips of a bike. Which property makes it suit?
- a) Rubber is see-through.
- b) Rubber is grippy. ← key
- c) Rubber is hard.
- d) Rubber is shiny.
Why it is this type: Medium because: the verdict is given and the reason is picked — the job's need has to be supplied by the student.
The why line (what a student reads after answering): Handle grips need to grip your hands. / Rubber is grippy. / So being grippy is the property that makes rubber suit the grips.
Recommendation: Approve as the exemplar
Topic 19 · Sinks, floats, sticks to a magnet: choosing materials · Type 9 · bank item PP-7 · tests MAT3-061
MediumMCQType 9 — a material picked for a fresh job with the job's need described: which property suits
Aisha picks glass for the walls of a greenhouse, so that light gets to the plants. Which property of glass suits the job?
- a) Glass is see-through. ← key
- b) Glass is hard.
- c) Glass is smooth.
- d) Glass is shiny.
Why it is this type: Medium because: the job's need is described ("so that light gets to the plants"), not named, and mapped to the coined property. James (29 Sep): "transparent is also a correct answer" — so it is never typed and transparent is never a distractor; the lesson's coin is see-through. (The former distractor "Glass is heavy" was replaced: the topic never says heavy.)
The why line (what a student reads after answering): The greenhouse walls need to let light through. / Glass is see-through. / So being see-through is the property that suits the job.
Recommendation: Approve as the exemplar
Topic 19 · Sinks, floats, sticks to a magnet: choosing materials · Type 6 · bank item PP-8 · tests MAT3-061 MAT3-008
HardMCQType 6 — a magnet-test table of four materials for a notice board that magnets must hold papers to: which material suits
drawing table_pp_board
Dilan tested four materials for a notice board that magnets must hold papers to. Which material suits the board?
- a) cork
- b) plastic
- c) aluminum
- d) steel ← key
Why it is this type: Hard because: two skills — the job's need is turned into "needs a magnetic material" (Lesson 4 (Say why that material)), then the test table is read for the material that has it (Lesson 2 (Does a magnet pull it? Sort them)). The table's cells are the test's yes / no, never the option words' verdict.
The why line (what a student reads after answering): Magnets must stick to the board, so the board needs a magnetic material. / Dilan's table says the magnet pulls steel and not cork, plastic or aluminum. / Steel is magnetic. / So steel suits the board.
Recommendation: Approve as the exemplar
Topic 19 · Sinks, floats, sticks to a magnet: choosing materials · Type 8 · bank item PP-9 · tests MAT3-061 MAT3-007
HardMCQType 8 — a sink-or-float table of four materials for a toy sailboat that must float: which material suits
drawing table_pp_toy
Rocco wants a toy sailboat for the pond that floats. He tested four materials in water. Which material suits the sailboat?
- a) steel
- b) wood ← key
- c) stone
- d) glass
Why it is this type: Hard because: two skills — the job's need (floats, Lesson 4 (Say why that material)) then the table read for the material that does (Lesson 1 (Does it sink or float?)). Was typed ("wood"); James's tightened test — a typed answer that is one of the things in view is an MCQ — makes it an MCQ.
The why line (what a student reads after answering): A toy sailboat needs a material that floats. / Rocco's table says wood floats. / Steel, stone and glass sink. / So wood suits the sailboat.
Recommendation: Approve as the exemplar
Topic 19 · Sinks, floats, sticks to a magnet: choosing materials · Type 10 · bank item PP-10 · tests MAT3-008
HardtypedType 10 — a magnet comes close to a steel thing and it jumps up: type the word for this property
text entry
A magnet comes close to a steel nut, and the nut jumps up to it. Type the word for this property of the nut.
Accepted answers (typed): term_accept("magnetic") — magnetic · a magnetic · the magnetic · its magnetic · it is magnetic · it's magnetic · being magnetic — plus magnetik · magnettic · magnetick · magnetec · magentic · is magnetic · the nut is magnetic.
Why it is this type: Closed because: one lexicon term; the stem states the test and its result and never the definition; no second coined word covers it (TOPIC["synonyms"] is empty). / Hard because: the coined word is PRODUCED, not recognised, from a case that does not state the definition (typing does the job the vault reserves it for: recall of an examinable term).
The why line (what a student reads after answering): The magnet pulls the nut. / A thing a magnet pulls is magnetic. / So the nut is magnetic.
Recommendation: Approve as the exemplar
The lessons (4)
Each lesson in teaching order: its one-line summary, the article, the script and the quiz, then your ruling.
Topic 19 · Lesson 1
Lesson 1 Does it sink or float?
a big wooden log and a small steel nail; Fidel says the log will sink and the nail will float; the test (lower it in, let go, watch where it ends up); the log floats, the nail sinks, so you cannot tell by looking; the table, one row per object; a stone, a cork, a candle stub mostly under the water ("It is not on the bottom, so it floats" — the boundary sentence the reviewer asked for). Nothing says why; "density" is nowhere. Quiz: eight drawn tanks on sinks / floats, a table read, the procedure, two claims.
Topic 19 · Lesson 2
Lesson 2 Does a magnet pull it? Sort them
two paperclips of the same shape, one steel, one plastic; the magnet takes one; "the stuff an object is made of is called its material"; a nail, a wooden block, the steel can and the aluminum can from Topic 4; the sort into two groups; the rule. Steel is never a piece of cutlery. Quiz: Topic 4 retrieved first, drawn tests on the two-group set, a drawn sort with one object misplaced, three claims, the term last.
Topic 19 · Lesson 3
Lesson 3 Mix two materials to do a job
Yoel's sand brick falls to bits; three bricks the same size (sand, clay, sand and clay), dried the same, the same push: bits, cracks, whole; "only what the bricks are made of is different, so this is a fair test" (Topic 7's word, retrieved first in the quiz); flour, water, dough. Quiz: table reads, three fair-test yes / no items, the one thing that changes.
Topic 19 · Lesson 4
Lesson 4 Say why that material
Effie slips in her socks and stops slipping in rubber soles; "a sole needs to grip; rubber is grippy; so rubber suits a sole"; a glass sole does not; a window (glass), a raincoat (plastic; paper soaks up water), a pillow (cotton); the two questions (what does the job need? which material has it?); "whether a thing floats, and whether a magnet pulls it, are properties too — a raft needs a material that floats; wood floats, like the log did." Quiz: which material suits, which property makes it suit, three claims, a bath toy that floats (cork), a fridge door a magnet must stick to (steel), the typed property last.
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