Answer:
Na2SO4 is equal to 0.0070401642780093 mole.
Explanation:
Potassium oxide: K₂O.
There's no need for prefixes since K₂O is an ionic compound.
<h3>Explanation</h3>
Find the two elements on a periodic table:
- Potassium- K- on the left end of period four.
- Oxygen- O- near the right end of periodic two.
Elements on the bottom-left corner of the periodic table are metals. Those on the top-right corner are nonmetals.
- Potassium is a metal,
- Oxygen is a nonmetal.
A metal and a nonmetal combine to form an ionic compound. Potassium oxide is likely to be an ionic compound. It contains two types of ions:
- Potassium ions: Potassium is group 1 of the periodic table. It is an alkaline metal. Like other alkaline metals such as sodium Na, potassium K tends to lose one electron and form ions of charge +1 in compounds. The ion would be K⁺.
- Oxide ions from oxygen: Oxygen is the second most electronegative element on the periodic table. It tends to gain two electrons and form the oxide ion
when it combines with metals.
The two types of ions carry opposite charges. They shall pair up at a certain ratio such that they balance the charge on each other. The charge on each ion is twice that on a 
ion. Each would pair up with two . Hence the subscript in the formula: 
.
There are two classes of compounds:
- Covalent compounds, which need prefixes, and
- Ionic compounds, which need no prefix.
Prefixes are needed only in covalent compounds. For instance in the covalent compound carbon dioxide 
, the prefix di- indicates that there are two oxygen atoms in the formula . However, there's no need for prefix in ionic compounds such as 
.
Answer:
- 1. Dimensions: The sheet can be cut into several smaller pieces.
- 2. Shape: the sheet can be formed into a paper ball or any other shape (using origami for example).
- 3. Color: You can use crayons to paint the sheet and change its color.
Explanation:
<em>Physical changes</em> do not change the chemical properties. They do not transform the compounds that form the substances. They do not break and or form chemical bonds.
When you change the form, the state (solid, liquid or gas), the color, you are just changing physical properties.
Only chemical changes change the compounds that form the substance. For instance, if you burn the <em>sheet of paper</em>, then you are causing a chemical change because the organic matter in the paper will react with oxygen forming CO₂ and water, but by cutting, folding, smashing, or coloring with crayons, the compounds in the<em> sheet of paper</em> do not change.
When there is an increase in pressure, the equilibrium will shift towards the side of the reaction with fewer moles of gas. When there is a decrease in pressure, the equilibrium will shift towards the side of the reaction with more moles of gas.
<span>The metal also gives off heat in the form of radiation.
Just took the test and got it right, using a process of elimination based on what you know helps. Hope this helps!</span>
