Answer:
A. 11
Explanation:
atoms are made of three types of sub atomic particles - protons, neutrons and electrons
Protons are positively charged, electrons are negatively charged and neutrons are neutral.
Protons and neutrons are located inside the nucleus and electrons orbit around the nucleus in energy shells.
Atoms make up an element and atoms are neutral charged with an equal number of protons and electrons. Neutral atom of sodium would therefore have an equal number of positive charges and negative charges.
Since Na has 11 protons, for it to be neutral it would have 11 electrons
Answer: X is a Solid; Y is a Gas
Explanation:
There are three (3) states of matter. They are: Solid, Liquid and Gases.
Substance X and Y, belong to the states of matter.
A Solid is a substance that retains its SIZE and SHAPE without need of a container (as opposed to a liquid or gas).
Thus, it will most likely be concluded that: substance X is a Solid; while Y is a Gas
1. <span>The region in which an electron is most likely to be found is called an orbital.
2. </span>An atom in which an electron has moved to a higher energy level is in an excited state.
3. When Mendeleev organized elements in his periodic table in order of increasing mass, elements with similar properties were in the same column.
4. Mendeleev’s periodic table was useful because it enabled scientists to predict properties of unknown elements.
1 mol is (always) the same number of units: 6.02 * 10^23 units.
So 0.5 moles of any gas has the same number of molecules.
Also, we know by the ideal gas laws that a give number of molecules of any gas will occupy the same volume.
Given that the three gases have the same number of atoms in the molecular fomula (2), 0.5 moles will also have the same number of atoms.
g.f.w. stands for grams formula weight and that is different for all of them, because gfw is calcualted from the atomics masses of each atom in the molecule.
Then at STP (standard temperature and pressure) conditions 0.50 moles of any of the gas:
- will contain the same number of molecules,
- will contain the same number of atoms
- will occupy the same volume.