A mole is the assemblage of 6.022×10^23 ions.This number is also known as Avogadro Number.
Avogadro constant=6.022×10^23 mol^-1
Answer:
H2 & F2
Explanation:
A covalent bond is formed when an electron is shared between two atoms. The two electrons of the covalent bond are positioned between the nuclei of the both bonding atoms. The electron pair of the bond may be equidistant from the nucleus of the two atoms or nearer to the nucleus of one of the bonding atoms than the other depending on the relative electro negativities of the both bonding atoms.
For homonuclear covalent bonds, there is no electro negativity difference between the bonding atoms. A single line may be used to indicate the shared electron pair between the two atoms.
Hydrogen and fluorine form homonuclear covalent diatomic compounds in which only a single electron pair is shared between bonding atoms. A single covalent bond is found connecting the two bonding atoms, hence the answer.
Answer:
Here is a bunch of info from my lesson to help you out...
Explanation:
All matter has physical and chemical properties. Physical properties are characteristics that scientists can measure without changing the composition of the sample under study, such as mass, color, and volume (the amount of space occupied by a sample). Chemical properties describe the characteristic ability of a substance to react to form new substances; they include its flammability and susceptibility to corrosion. All samples of a pure substance have the same chemical and physical properties. For example, pure copper is always a reddish-brown solid (a physical property) and always dissolves in dilute nitric acid to produce a blue solution and a brown gas (a chemical property).
Physical properties can be extensive or intensive. Extensive properties vary with the amount of the substance and include mass, weight, and volume. Intensive properties, in contrast, do not depend on the amount of the substance; they include color, melting point, boiling point, electrical conductivity, and physical state at a given temperature. For example, elemental sulfur is a yellow crystalline solid that does not conduct electricity and has a melting point of 115.2 °C, no matter what amount is examined (Figure 1.3.1
1.3.
1
). Scientists commonly measure intensive properties to determine a substance’s identity, whereas extensive properties convey information about the amount of the substance in a sample.
Answer:
41.51 g of CO
Explanation:
The balance chemical equation for given double displacement reaction is,
Fe₂O₃ + 3 CO → 2 Fe + 3 CO₂
Step 1: <u>Calculate moles of Fe₂O₃:</u>
Moles = Mass / M.Mass
Moles = 78.9 g / 159.68 g/mol
Moles = 0.494 moles
Step 2: <u>Calculate moles of CO:</u>
According to equation,
1 mole of Fe₂O₃ reacted with = 3 moles of CO
so,
0.494 moles of Fe₂O₃ will react with = X moles of CO
Solving for X,
X = 0.494 mol × 3 mol ÷ 1 mol
X = 1.482 moles of CO
Step 3: <u>Calculate Mass of CO as:</u>
Mass = Moles × M.Mass
Mass = 1.482 mol × 28.01 g/mol
Mass = 41.51 g of CO
Answer:
Explanation:
The area of a telescope lens is 6.668 × 10³ mm²
We need to convert the area in ft².
We know that,
It means,
or
So, the required answer is .
