Answer:
Group 18, also known as the Noble Gasses
Explanation:
Atoms strive for full stability by gaining or losing electrons to get 8 valence electrons in their valence shell, but Group 18 already has 8 electrons in their valence shell, and are therefore already stable in their ground state.
To work this out you do 400÷20=20
Polyethene is a polymer composed of repeating units of the monomer ethene.
The properties of polyethene are as follows:
- density- ranges 0.857 g/cm3 to 0.975 g/cm3.
- specific heat capacity is 1.9 kJ/kg.
- melting temperature is approximately 110 °C.
<h3>What are polymers?</h3>
Polymers are large macromolecules consisting of long repeating chains of smaller molecules known as monomers.
An example of a polymer is polyethene composed of repeating units of the monomer ethene.
The density of polyethylene ranges 0.857 g/cm3 to 0.975 g/cm3.
The specific heat capacity of polyethene is 1.9 kJ/kg.
The melting temperature of polyethene is approximately 110 °C.
Learn more about polyethene at: brainly.com/question/165779
Vol.250 before its to much pressure
Answer:
19 g
Explanation:
Data Given:
Sodium Chloride (table salt) = 50 g
Amount of sodium (Na) = ?
Solution:
Molecular weight calculation:
NaCl = 23 + 35.5
NaCl = 58.5 g/mol
Mass contributed by Sodium = 23 g
calculate the mole percent composition of sodium (Na) in sodium Chloride.
Since the percentage of compound is 100
So,
Percent of sodium (Na) = 23 / 58.5 x 100
Percent of sodium (Na) = 39.3 %
It means that for ever gram of sodium chloride there is 0.393 g of Na is present.
So,
for the 50 grams of table salt (NaCl) the mass of Na will be
mass of sodium (Na) = 0.393 x 50 g
mass of sodium (Na) = 19 g
