The density of the gas is 1.45 g/L.
The mass of the gas is 0.0707 g.
The volume of the gas is 48.9 mL.
Density = mass/volume = 0.0707 g/48.9 mL = 1.45 × 10⁻³ g/mL = 1.45 g/L
Answer:
Number of neutrons: 44
Number of protons: 34
Number of electrons: 36
Explanation:
The atomic number of Se (Selenium) is 34
Mass number is 78
Number of neutrons = mass number - atomic number = 78 - 34 = 44
Number of protons is the same as the atomic number
Number of protons = 34
Selenium ion has a charge of -2. This means it accepts two more electrons
Number of electrons = atomic number + 2 = 34 + 2 = 36
Answer:
Non-metals tend to gain electrons
Explanation:
Since you didn't have any extra information about the question I'll be presenting an example from my own textbooks that I've used.
An example of a direct observation is listening to a cricket chirp at night, and counting the number of chirps per minute.
Direct Observation is where the evaulator watches the subject in their usual habitat without disrupting or altering it.
Dry ice is made with co2 and if you pour water over it smoke comes as the ho2 is reacting with the co2
