| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.66 |
| Score | 0% | 73% |
Which of the following substances gives up negatively charged hydroxide ions (OH-) when dissolved in water?
base |
|
hydrogen |
|
ion |
|
acid |
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.
These clouds grow upward and can develop into cumulonimbus or thunderstorm clouds.
stratus clouds |
|
nimbus clouds |
|
cumulus clouds |
|
cirrus clouds |
Cumulus clouds are large, puffy, mid-altitude clouds with a flat base and a rounded top. These clouds grow upward and can develop into a cumulonimbus or thunderstorm cloud.
An endoskeleton (internal skeleton) is a charateristic of __________ animals, including humans.
vertebrate |
|
spiny |
|
arthropod |
|
sentient |
An endoskeleton (internal skeleton) is a charateristic of vertebrate animals, including humans.
The ovum and oviduct are part of which bodily system?
reproductive |
|
digestive |
|
circulatory |
|
nervous |
Approximately every 28 days during female ovulation an egg (ovum) is released from one of the ovaries and travels through the oviduct (fallopian tube) and into the uterus. At the same time, the endometrial lining of the uterus becomes prepared for implantation.
The gravitational interaction of Earth and the Moon is responsible for which of these?
tides |
|
seasons |
|
the northern lights |
|
day and night cycle |
Tides are caused by the gravitational interaction of Earth and the Moon.