Answer:
14 H i think , but i believe that thats the answer
We have to look for safe and non - hazardous characterstics when trying to find new propellants.
<h3>What are propellants ?</h3>
Propellants are any gas, liquid, or solid the expansion of which can be used to impart motion to another substance or object.
The Desirable properties for propellant combinations are ;
- low molecular mass and high temperature of reaction products (for high exhaust velocity),
- high density (to minimize tank weight),
- low hazard factor (e.g., corrosivity and toxicity),
- low environmental impact,
- low cost.
Learn more about propellants here ;
brainly.com/question/1395855
#SPJ1
Circumpolar constellations stay in the sky. Because of the rotation of the Earth and its orbit around the Sun, we divide the stars and constellations into two groups. Some stars & constellations never rise nor set, and they are called circumpolar.
The density formula is:
density=mass/volume.
d=3.5g/2cm^3
d=1.75 g/cm^3
The density of the sample is 1.75 g/cm^3.
Answer:
A.Lithium (Li)
since fluorine and nitrogen gain electron and becomes negative ion.
since magnesium loose two electron.
