The element symbol in chemistry comprises atomic number and mass number.
Atomic number is written on the top of element and mass number is written at the bottom.
For eg:
If Y is an element that is having atomic number a and mass number x. Then its denotion will be:
ᵃYₓ.
So here ⁹F₁₈.₉₉
Here 18.99 will denote mass number while 9 will denote atomic number.
Answer:
1. 1.25 mol ants x 6.02*10^23 ants/1 mol ants = 7.53*10^23 ants
2. 4.92*10^26 pencils x 1 mol pencils/6.02*10^23 pencils = 817 mol pencils
3. 0.26 mol molecules x 6.02*10^23 molecules/1 mol molecules = 1.6*10^23 molecules
4. 3.46*10^19 molecules x 1 mol molecules/6.02*10^23 molecules = 5.75*10^-5 mol molecules
5. 5.3*10^20 atoms x 1 mol atoms/6.02*10^23 atoms = 8.8 mol atoms
6. 0.11 mol atoms x 6.02*10^23 atoms/1 mol atoms = 6.6*10^22 atoms
I would suggest looking into "dimensional analysis" for help with this type of material. Dimensional analysis will stick with you all throughout chemistry, so picking it up will be extremely beneficial.
Answer:
7.5 pounds per square-inch
At sea level, one square-inch of any surface has about 15 pounds of air sitting on top of it. At 18,000 feet, that same square inch has only 7.5 pounds per square-inch (psi) exerted on it.
Answer:
Explanation:
The difference between Polycrystalline and Amorphous materials is given as:
Polycrystalline:
- The atoms in the crystal lattice are arranged in an ordered manner.
- The particles in the crystal posses a particular geometry
- The crystal lattice have a specific temperature known as its Melting Point.
Amorphous:
- There is no specific order in the arrangement of particles in the crystal.
- They do not have any particular geometry.
- There is no specific temperature but a range of temperature in which the crystal melts.
The properties of crystalline materials can be constrained by modifying the grain size at the hour of the amalgamation. The mechanical properties can be improved by choosing the grain size so that the quantity of disengagements and grain limits are expanded.
Usually this should be possible by diminishing the grain size, yet it additionally relies on a ton of different elements relying on the application. The quality of the material is expanded when the grain size is decreased.
Usefulness of smaller grains:
At the point when the size of the grains is decreased to a degree of 100 nm to 1000 nm, we can say we had acquired smaller grain which can be called as ultra-fine grain materials.
These can be utilized widely for the assembling of nanomaterial which are having a tremendous assortment of utilization and the new regions of use are expanding by step by step.
Usefulness of smaller grains:
Larger grains size is valuable in light dissipating applications, huge size grain has high perceivability to the light and it very well may be utilized in dispersing applications. Larger molecule size is utilized in specific responses to restrict the reactivity to a specific degree.
Applications of Amorphous Material:
- The amorphous carbon is utilized for the production of Ta-C films which can be utilized for the applications in ultra-flimsy defensive coatings for attractive plates, in cells, batteries and sun powered cells, to keep up inactive layers in electronic gadgets, etc.
- Amorphous silicon is utilized for the assembling of the Thin Film Transistor (TFT) which is in the end be utilized for computerized x-beam picture detecting, coordinated shading sensors, sensors for CMOS cameras, light-radiating diodes, and so on.
