Elements always exist as pair of atoms called molecules .
Explanation:-
- The material which has only one types of similar atoms called element .
- Ex:-Sodium,Carbon etc
Explanation:
2. 
First, we need to find the number of moles of 
at 300K and 1.5 atm using the ideal gas law:
Now use the molar ratios to find the number of moles of ethane to produce this much .
Finally, convert this amount to grams using its molar mass:
3. 
Convert 75 g Zn into moles:
Then use the molar ratios to find the amount of H2 produced.
Now use the ideal gas law 
to find the volume of H2 produced at 23°C and 4 atm:
Answer:
Solid: calcium and potassium
Liquid: mercury and bromine
Gaseous: oxygen and fluorine
Explanation:
Matter exists in three different states namely: solid, gaseous and liquid. Elements that are found in nature are classified as matter. Since, these elements are grouped as matter, they can either be found as either solids, liquids or gases at normal temperature and pressure.
At normal temperature (20°C or 293K) and pressure (1 atm), the following elements are found to exists in the respective state of matter:
Solid: Calcium (Ca) and potassium (K)
Liquid: Mercury (Hg) and bromine (Br)
Gaseous: Oxygen (O) and fluorine (F)
The forces between particles are called intermolecular forces. A strong intermolecular force means that the particles are tightly paced and is associated with the solid phase. Moderate intermolecular force is associated with the liquid state and little to no intermolecular force is associated with the gaseous state. Temperature has a direct effect on the state of matter in which the substance exists has. Generally speaking, a rise in tempreature changes a substance from the solid to liquid phase and from liquid to gaseus phase. The reverse is true, if the temperature lowers then the substance will go from gas to liquid and liquid to solid. It is important to not that temperature affects intermolecular forces. As the temperature increases then the individual particles become excited and gain enough energy to over the intermolecular forces and so the particles seperate from each other.
We know the sun is primarily made from hydrogen and helium on the basis of its spectrum.
<h3>What is Sun's spectrum?</h3>
Sun's spectrum refers to the light of the Sun whose wavelength spectra can be used to identify atomic composition.
Thus spectrum (Sun's spectrum) initiates with the red light (700 nm) and ends with the blue (380 nm).
In conclusion, we know the sun is primarily made from hydrogen and helium on the basis of its spectrum.
Learn more about the Sun's spectrum here:
brainly.com/question/2021598
#SPJ12
