The atomic radius is a measure of the size of an atom. The atomic radius is defined as one-half the distance between the nuclei of two identical atoms that are bonded together.
r is atomic radius of an atom and d is distance between the nuclei of two identical atoms
Atomic radius is dependent on the type of bond present. Types of bonds can be grouped as five descriptive types.
<span>Ionic bondsCovalent bondsMetallic bondsvan der Waals bondsHydrogen bonds</span>
Units used to measure atomic radius:
<span><span>Angstroms (Å): This the most common unit used. Equivalent to 1.0 x 10-10 meters.</span><span>Nanometer (nm): Equivalent to 1.0 x 10-9 meters.</span><span>Picometer (pm): Equivalent to 1.0 x 10-12 meters.</span></span>
Period Trends
As you move left-to-right across a period, in general (not including the noble gases), atomic radius decreases.
As you go left-to-right across a period, electrons are added to the same energy level. At the same time, protons are being added to the nucleus increasing positive charge in the nucleus. Increased positive charge in the nucleus pulls the electrons closer to the nucleus resulting in a smaller atomic radius.
Group Trends
As you move down a group, in general, atomic radius increases.
As you move down a group the number of electrons increases, thus increasesing the number of energy levels. The outermost orbital increases in size when you move down the group making the atom larger. Therefore, the atomic radius increases as the group and energy levels increase.
Answer:
Energy
Explanation:
Paper is oxidized in the presence of oxygen. This reaction however proceeds very slowly until energy is supplied to the system. This implies that the reaction is not spontaneous at room temperature. A spontaneous reaction takes place without any need for external supply of energy.
The need for supply of external energy must be as a result of the high activation energy required for the reaction to go to completion. If a chemical reaction has a high activation energy, it will require an external supply of energy in order for such reaction to occur.
Answer:
The nanometre (international spelling as used by the International Bureau of Weights and Measures; SI symbol: nm) or nanometer (American spelling) is a unit of length in the metric system, equal to one billionth (short scale) of a metre (0.000000001 m).
Answer:
393 cm
Explanation:
Step 1: Given and required data
- Density of liquid methylene bromide (ρ): 2.50 g/mL (2.50 g/cm³)
- Earth's gravity (g): 9.81 m/s²
- Atmospheric pressure (P): 0.950 atm
Step 2: Convert 0.950 atm to Pa (N/m²)
We will use the conversion factor 1 atm = 101325 Pa.
0.950 atm × 101325 Pa/1 atm = 9.63 × 10⁴ Pa
Step 3: Convert 2.50 g/cm³ to kg/m³
We will use the conversion factors:
Step 4: Calculate the height (h) of the liquid column
We will use the following expression.
P = ρ × g × h
h = P / ρ × g
h = 9.63 × 10⁴ Pa / (2.50 × 10³ kg/m³) × 9.81 m/s²
h = 3.93 m = 393 cm
Answer:
Because , the advantage of steam distillation over simple distillation is that the lower boiling point reduces decomposition of temperature-sensitive compounds. Steam distillation is useful for the purification of organic compounds, although vacuum distillation is more common
Explanation:
