Ch. 1.5 Flashcards
Throughout history, people have been using different ways to make measurements. The older ways were usually ______________ _____________________ than the modern ones.
Less accurate
Measurements:
Length:
Past: ______________
Now: _________________
Arms, ruler
Measurements:
Time:
Past: ________________
Now: ____________________
Sundial, watch/ clock
Instruments used for measuring length
1.
2.
3.
- Metre rule
- Half-metre rule
- Measuring tape
When measuring the length of an object with a ruler, we should read the scale from ____________________ to make sure that we take an accurate reading.
Vertically above
Units of measuring length: 1. 2. 3. 4.
- Metres (m)
- Centimetres (cm)
- Millimetres (mm)
- Kilometres (km)
1 km= ?m
1000
1 m= ? cm
100
1 cm= ? mm
10
Measuring volume: Units of measuring: 1. 2. 3. 4.
- Millilitres (mL)
- Litres (L)
- Cubic centimetres (cm3)
- Cubic metres (m3)
1 L= ? mL
1000
1 mL= ? cm3
1
1 m3= ? cm3
1,000,000
What is the curved surface of a liquid in a measuring cylinder called?
Meniscus
To take an accurate reading with a measuring cylinder, our eyes should be _________________.
At the same level as the bottom of the meniscus
How do we measure the volume of a rectangular/ cube object?
- Measure the length, width and height
2. Calculate length X width X height
How to measure the volume of a small irregular object?
- Add water to a ______________ until it is about ____________ and record the volume of water
- Tie object with a _______________
- Lower object into water in the _________________ and record volume of water
- __________________-_________________=volume of object
Measuring cylinder, half-full, string, measuring cylinder, original volume, new volume
Measuring the volume of a large irregular object
- Tie object with string
- Place a ________________ ______ near edge of bench with pout pointing ______________
- Hold __________________ ______________ below the spout of the _________________ ____________ and pour water into ______________ _______ until a little water runs out of the spout and pour the water away
- Hold the empty ______________ ________ below the spout and slowly lower the object into the water in the ______________ _______
- Measure volume of water that ___________ _______ of ________________ ______.
Displacement can, outwards, measuring cylinder, displacement can X2, measuring cylinder, displacement can, flows out, displacement can
Instruments for measuring mass 1. 2. 3. 4. 5. 6.
- Triple beam balance
- Spring balance
- Lever balance
- Top pan balance
- Electronic balance
- Bathroom scale
Which type of instrument used for measuring mass is the most precise and commonly used in the lab?
Electronic balance
What is the precision of an electronic balance?
Up to 2 decimal places
The ______________/ ____________ button on an electronic balance sets the balance reading to zero.
Re-zero/ tare
When is the ‘re-zero’/ ‘tare’ function useful?
When we’re measuring the mass of a substance in a container.
Steps of using an electronic balance for measuring the mass of a substance in a container
- Put ___________ ______________ on balance
- Press the ‘_________’ button to set the balance reading to zero so that the mass of the container is not counted
- Add the substance to the container and you can thus ___________ measure the mass of the substance
Empty container, re-zero, directly