Answer:
- The standard form of a chemical element is the natural mixture of several isotopes of the same element, which is atoms with the same number of protons but different number of neutrons, while an isotope is a particular kind of atom with a definite number of neutrons.
Explanation:
A <em>chemical element</em> is a pure substance formed by atoms with the same atomic number (number of protons). This is because it is the number of protons what identifies an element.
For example: oxygen is a chemical element, so oxygen is formed by only atoms of oxygen, and the atomic number of those atoms is 8, because every oxygen atom has 8 protons.
Nevertheless, some atoms of oxygen, may have different number of neutrons. Isotopes are different kind of atoms of the same element, which only differ in the number of neutrons. So, some atoms of oxygen will have 8 neutrons, other 9 neutrons, and other 10 neutrons (those are the stable isotopes of oxygen).
That difference in neutrons, is generally accepted that, does not modifiy substantially the chemical properties of the element, but the mass number. So, the isotopes with more neutrons wil be heavier, and the isotopes with less neutrons will be lighter.
- Mass number = number of protons + number of neutrons.
In general a chemical element is formed by a mixutre of isotopes of the same element.
M = 0,23kg = 230g
d = 1g/cm³
V = 230g / 1g/cm³ = 230cm³ = 0,23L
This picture represents electrons
Answer:
<u>B. In a wet, hilly area</u>
Explanation:
We know that for a landslide to happen, there has to be a down hill slope so it can fall.
This eliminates answers C, D and E.
So we are left with A and B
Now we can look at this in a real life scenario. If you have ever walking on wet ground, you will know that is weaker than dry ground. Knowing this, we know the answer will have to be answer B.
I think the compound that has the highest boiling point is CCl4
This is because it has four Carbon-Chloride bonds , while the others have three, two and one and Carbon-hydrogen bonds.
Carbon-Chloride bonds are stronger compared to the Carbon-hydrogen bond, therefore in this case the compound with more C-Cl will have more boiling point.
