Lab Safety and Scientific Equipment — Answers
Answer sheet with model answers and success criteria for the Year 7 working scientifically worksheet.
Success TutoringWorksheetsAnswer sheetYear 7 · Science · Working ScientificallyLab Safety and Scientific Equipment — Answers
Part A: Staying safe in the lab
Read the passage, then answer the questions.
A science laboratory has hazards such as heat, glass, electricity and chemicals. Always follow your teacher's instructions, wear safety glasses, tie back long hair, keep bags out of walkways and report all spills, breakages and injuries immediately.
Chemical containers carry hazard symbols that warn you of the type of danger. Read the label before you use any substance.
- APick up the pieces quickly with your hands.
- BTell your teacher straight away and keep others away from it.
- CPush the pieces under the bench.
- DKeep working and clean it up at the end.
Answer: Tell your teacher straight away and keep others away from it.
Broken glass and spilled chemicals can cause injuries. Your teacher will clean it up safely with the right equipment.
- APut your nose right over the container and breathe in deeply.
- BGently waft the air above it towards your nose with your hand, only if your teacher says to.
- CTaste a tiny amount instead.
- DHeat it first so the smell is stronger.
Answer: Gently waft the air above it towards your nose with your hand, only if your teacher says to.
Wafting lets you detect a smell without breathing in a large amount of a possibly harmful gas.
Answer: False
Eye protection should be worn whenever chemicals, glassware or heating are being used, because splashes can happen at any time.
Answer: True
Loose hair can easily catch fire.
Answer: False
Food and drink can become contaminated with chemicals. Never eat or drink in a lab.
- flame symbol
- test tubes dripping onto a hand and a surface
- skull and crossbones
- exclamation mark
- corrosive — can burn skin and damage materials
- flammable — catches fire easily
- toxic — can be poisonous even in small amounts
- harmful or irritant — can cause irritation or mild harm
Answer: flame symbol → flammable — catches fire easily; test tubes dripping onto a hand and a surface → corrosive — can burn skin and damage materials; skull and crossbones → toxic — can be poisonous even in small amounts; exclamation mark → harmful or irritant — can cause irritation or mild harm
Part B: Equipment and measuring
Choosing the right equipment makes measurements more accurate. A measuring cylinder measures volume much more accurately than the rough marks on a beaker.
Water curves where it meets the glass. This curve is called the meniscus. Read the scale at the bottom of the meniscus, with your eye level with it.
- measuring cylinder
- beaker
- tripod and gauze mat
- tongs
- evaporating dish
- electronic balance
- measures the volume of a liquid accurately
- supports a beaker above a Bunsen burner
- holds, mixes and heats liquids (volume marks are only approximate)
- heats a solution until the liquid evaporates
- pick up hot objects
- measures mass
Answer: measuring cylinder → measures the volume of a liquid accurately; beaker → holds, mixes and heats liquids (volume marks are only approximate); tripod and gauze mat → supports a beaker above a Bunsen burner; tongs → pick up hot objects; evaporating dish → heats a solution until the liquid evaporates; electronic balance → measures mass
Answer: 46 mL
- 3 marks × 2 mL = 6 mL
- 40 + 6 = 46 mL
Answer: False
Beaker marks are only approximate. A measuring cylinder (or a pipette) measures volume more accurately.
Answer: meniscus
Part C: Using a Bunsen burner
A Bunsen burner burns gas to heat things. When the air hole is closed, it makes a yellow, wavy safety flame that is easy to see. When the air hole is open, it makes a hotter blue flame used for heating.
- Athe yellow safety flame (air hole closed)
- Bthe blue roaring flame (air hole open)
- Cno flame — blow it out each time
- Dthe hottest possible flame
Answer: the yellow safety flame (air hole closed)
The yellow safety flame is easy to see, so no one will accidentally touch it or put something near it.
- AIt is cooler and safer.
- BIt is much hotter and does not leave soot on equipment.
- CIt is easier to see.
- DIt uses no gas.
Answer: It is much hotter and does not leave soot on equipment.
With the air hole open the gas burns completely, giving a hotter, clean blue flame.
Answer: True
Someone could knock it over or touch the flame, or nearby objects could catch fire. Turn it off or watch it at all times.
Model answer: 1. Put on safety glasses and tie back long hair, so splashes cannot reach your eyes and hair cannot catch fire. 2. Place the Bunsen burner on a heatproof mat, away from paper and bags, so nothing nearby catches fire. 3. Fill the test tube no more than one-third full, so the water is less likely to boil over. 4. Light the burner with the air hole closed (yellow safety flame), then open it to a blue flame for heating. 5. Hold the test tube with a test-tube holder at an angle, so your hand stays away from the heat. 6. Point the open end away from yourself and others, and move it gently in the flame, so if the water spits suddenly it cannot hit anyone. 7. Turn the flame back to yellow or off when finished, and let the test tube cool before touching it.
Success criteria:
- Logical step-by-step method
- At least four relevant safety precautions
- Explains the reason for each precaution
- Includes pointing the test tube away from people
Marking tips
- Give credit for correct method even when the final answer slips — the working shows where the thinking went right.
- For open-ended tasks, use the success criteria as a checklist rather than looking for one "right" answer.
- Celebrate what went well first, then pick one thing to work on next.