Answer:
C. At least five mass-extinction events have occurred during the last 500 million years.
Explanation:
- The history of mass extinct is related to the five mass extinctions that are caused over by the 350 million years n which many species have disappeared in there short geologic time.
- A massive extinction is caused in the Permian Triassic extinction event i.e about 250 mn years ago which on an estimate has killed 90% of the species.
- The Cretaceous–Paleogene extinction event that occurred over 66 million years ago is known to have wiped out the dinosaurs and many other species.
Matter is anything that has mass. everything has matter, even the air.
3. IV:height of drop DV:height of bounce CV: type of ball, place where ball is dropped, climate/wind
4. IV: battery type DV: time that it lasts CV: age of batteries, age of material (flashlights), type of materials (flashlights), size of batteries
5. IV:depth of water DV: temperature CV: amount of water in lake, temperature, climate/season
Answer:
The correct answer is 7.5 ml
Explanation:
The medicine contains 100 mg in 5 ml, that means that the concentration of the active ingredient is 100 mg/5 ml= 20 mg/ml
If we divide a concentration (in mg/ml) into a mass (in mg) we obtaine a volume (in mL). Thus, in order to calculate the mililiters of medicine which contain 150 mg of the active, we have to only divide mass (150 mg) into the concentration of active ingredient as follows:
mL = 
= 7.5 mL
Answer:
C
Explanation:
Protozoa have been classified into three trophic categories: the photoautotrophs which harness the sun's radiant energy in the process of photosynthesis; the photoheterotrophs, which although phototrophic in energy requirements, are unable to use carbon dioxide for cell synthesis and must have organic carbon compounds
