Answer:
Because each element has an exactly defined line emission spectrum, scientists are able to identify them by the color of flame they produce. For example, copper produces a blue flame, lithium, and strontium a red flame, calcium an orange flame, sodium a yellow flame, and barium a green flame. When you heat an atom, some of its electrons are "excited* to higher energy levels. When an electron drops from one level to a lower energy level, it emits a quantum of energy. ... The different mix of energy differences for each atom produces different colors. Each metal gives a characteristic flame emission spectrum
Moles of ammonium sulfate = 26.42/molar mass of (NH4)2SO4
= 26.42/132.14 = 0.19 mole.
Molarity = moles of ammonium sulfate/volume of solution
= 0.19/50x10^-3
= 3.8M
Answer:
Red was originally selected for the same reason. Over a century ago, red was a nice bright color that set fire apparatus apart from most vehicles on the road. Red became traditional, and most fire departments stayed with it. Some firefighters like yellow trucks, some prefer traditional red.
Ca, V, Cu, Kr
Remember a period is a the horizontal rows in the Periodic Table.