Answer:
Acceleration is the rate of change in velocity
I would say it is a chemical change because after a while, the nails start to rust. Now they only rust after about a week though. But rust is a chemical change.
The experimental control is the standard used as a comparison for the experimental groups.
For example, you may be trying to find out how different types of disinfectants affect bacterial growth. The control group would receive <em>no</em> disinfectant whereas the experimental groups would be the ones on which the disinfectants were tested.
Hope this makes sense!
Answer:
The metals in this group are lithium, sodium, potassium, rubidium, cesium, and francium. The gas hydrogen is also put in this group because it shares similar reactivity with the alkali metals.
I don't know if this is what you wanted or not sorry if it isn't
