Answer:A- It is important to keep the developing chamber covered with plastic wrap during the development of the chromatogram so the solvent vapor can saturate the air in the chamber, the solvent does not evaporate and the chromatogram develops properly and shows the correct cations present.
1.) the geologic time scale is a system of chronological dating that relates geologic structure to geologic events. it is a model because it measures and describes events and relationships in geologic history.
2.) the paleozoic period was roughly from 245 million years ago to 545 million years ago.
3.) the dinosaurs lived in the mesozoic era, specifically the triassic period, which was roughly around 230 million years ago.
4.) the first early human relatives were found roughly around d the neogene period, about 25 million years ago, and is in the cenozoic era.
Group 2, or in the Alkaline Earth Metals section. This is due to the necessity to have a +2 charge to balance out or negate the -2 charge two Bromines carry.
Mass of gas produced : 15 g
<h3>Further explanation
</h3>
In general, the reaction takes place in the open air. If the reaction results in the form of gas as in combustion, the mass of the reaction results will be smaller than the original mass.
Conservation of mass applies to a closed system, where the masses before and after the reaction are the same
So In a closed/isolated system, the total mass of the substance before the reaction will be equal to the total mass of the reaction product.
Mass of solution A = 70 g
Mass of solution B = 35 g
Mass of mixture : 90 g
Mass of gas : X
Mass of gas X :
Answer:
1:C as all metal are good conductors of heat & electricity
2:D conductivity as it needs delocalized electrons normaly
3:B good conductors of heat & electricity
