| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.00 |
| Score | 0% | 60% |
Which of the following substances gives up positively charged hydrogen ions (H+) when dissolved in water?
base |
|
acid |
|
alkaline |
|
solution |
An acid is a substance that gives up positively charged hydrogen ions (H+) when dissolved in water. A base (alkaline) gives up negatively charged hydroxide ions (OH-) when dissolved in water. pH is a scale that measures of how basic or acidic a solution is. Numbered from 0 to 14, solutions with a pH of 7 are neutral, less than 7 are acidic, more than 7 are alkaline.
Which of these is matter than cannot be separated into different types of matter by ordinary chemical methods?
compound |
|
molecule |
|
element |
|
atom |
An element is matter than cannot be separated into different types of matter by ordinary chemical methods.
Which of the following is not true of light waves?
are mechanical waves |
|
can travel through a vacuum |
|
are electromagnetic waves |
|
travel faster than sound waves |
Unlike mechanical sound waves that require a physical medium for propagation, light waves are electromagnetic and can travel through empty space. Light waves are also much faster, travelling at 186,000 m/s vs. 343 m/s for sound waves.
Which of the following is not a method of heat transfer?
radiation |
|
convection |
|
conduction |
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reflection |
Heat is always transferred from warmer to cooler environments through conduction, convection, or radiation.
__________ and __________ pair to strengthen bones.
calcium, vitamin A |
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vitamin D, calcium |
|
iron, calcium |
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vitamin D, magnesium |
Vitamin D helps calcium strengthen bones while also aiding muscle, nerve, and immune system function.