<span>6 + x = 12. To evaluate an algebraic expression, you have to substitute a number for each variable and perform the arithmetic operations. In the example above, the variable x is equal to 6 since 6 + 6 = 12. If we know the value of our variables, we can replace the variables with their values and then evaluate the expression.</span>
Answer:
Chemical properties
Atomic number. The atomic number indicates the number of protons within the core of an atom.
Atomic mass. The name indicates the mass of an atom, expressed in atomic mass units (AMU).
Electronegativity according to Pauling.
Density.
Melting point.
Boiling point.
Vanderwaal's radius.
Ionic radius.
And many more.
Explanation:
You will want to find how many grams are in a whole mole so you know which element it is. To do this, find out how much of a mole you have.
4.95 x 10^23 atoms / 6.022 x 10^23 atoms (one whole mole of any element) = .8219860511 or ~82% of 1 mole
Now we know that, find what to multiply 20 g by to get the rest of the mole.
1 mole / .8219860511 mole = 1.216565657
20 g x 1.216565657 = ~24.33 g / mol
Now that you have grams per mole, you can look at the periodic table and the molar masses to see which this number is closely aligned.
Your answer is Magnesium (Mg), which has a molar mass of 24.305 g
C. You should ALWAYS ask the teacher if you don't get something; your friends could be wrong, don't guess it, and NEVER cheat. Hope this helps!!
Explanation:
Rutherford conducted an experiment in which he took a thin gold particle film on which he passes alpha- particles. He noticed that:
- Most of the alpha particles get through the film and can be detected by the detector.
- Around small portion of the alpha particle deflected at small angles.
- A very very few alpha particle (approximately 1 out of 1 million alpha particles) just retraced their path which means come back from the center.
He concluded that:
<u>Most of the space of the atom is empty and in the center of the atom , there is solid mass which is the cause of the alpha particles to come back. He gave the term nucleus to this solid mass.</u>
