Answer:
10.70grams
Explanation:
Density of a substance = mass/volume
At STP of a gas (standard temperature and pressure), the density of oxygen gas is 1.429 g/L
Hence, according to this question, in 7.49 L of oxygen gas, there would be:
Using D = m/V
1.429 = m/7.49
m = 1.429g/L × 7.49L
m = 10.70g
To be honest, I learned this in school so I'll tell you XD
The formula of sodium oxide is Na2O
Answer:
I am also beginners I don't know I am only completing this answer and sorry!!!!!!
Answer: C
Explanation:
According to Neils Bohr, atoms contain electrons which are arranged in energy levels. The energy levels proceed from the lowest to the highest. When energy is supplied to an atom,it moves from lower to higher energy levels. The higher energy level is known as the excited state. Excited states are short lived and atoms quickly return to ground state with emission of the absorbed energy in the form of visible light. This visible light must have one of the seven colours observed in the visible spectrum; Red, orange, yellow, indigo, blue, green, violet. Energy required for this excitation is supplied by heating the substance in a flame.
Answer:
Spectroscopy
Explanation:
They can determine its composition based on these wavelengths. The most common method astronomers use to determine the composition of stars, planets, and other objects is spectroscopy
