The physical properties of gadolinium, what does it mean in physics

Gadolinium is a silvery-white metal, malleable, with a melting point of 1313 °C, a boiling point of 3266 °C, and a density of grams. Gadolinium is magnetic at room temperature. Gadolinium is relatively stable in dry air and loses luster in humid air; Gadolinium has the highest thermal neutron capture surface and can be used as a reactor control material and protective material; Magnetized refrigeration with gadolinium salts can be achieved close to absolute zero.

ultra-low temperature. In 1880, Marignac of Switzerland separated "samarium" into two elements, one of which was confirmed by Solit to be samarium, and the other element was confirmed by Bois Baudeley's research, and in 1886, in order to commemorate the discoverer of yttrium, the pioneer of rare earths, the Dutch chemist Gado Linium, named this new element gadolinium. Gadolinium will play an important role in modern technological innovation.

CAS number. Element name: Gadolinium.

The amount of elements in the sun: (ppm):

Element content in seawater: (ppm): Pacific surface crust: (ppm):

Elemental atomic weight.

Oxidation states: main gd+2, gd+3

Other crystal structure: The unit cell is a hexagonal unit cell.

Unit cell parameter: a = pm

b = pm

c = pm

120° Vickers hardness: 570MPa

The propagation rate of sound in it: (m s) 2680 ionization energy (kj mol) m - m+

m+ -m2+ 1167

m2+ -m3+ 1990

m3+ -m4+ 4250

Relative atomic mass.

Common valence: +3

Electronegativity: Outer electron shell.

Arrangement: 4f7 5d1 6s2

Extranuclear electron configuration.

Number of nuclear charges: 64

Crystal type: close-packed hexagonal.

Isotope. and radiation: GD-148 [75Y] GD-150 [1800000Y] GD-152 (put [GD-154 GD-155 GD-156 GD-157 *GD-158 GD-159[ GD-160 GD-162[

Periodic table.

Location: 64

Distribution of electron shell: 2-8-18-25-9-2 electron shell: k-l-m-n-o-p

Electron affinity and energy: 0 kj·mol-1

First ionization energy.

594 kj·mol-1

Second ionization energy: 1170 kJ·mol-1

Third ionization energy: 0 kj·mol-1

Elemental density: g cm3

Elemental melting point:

Elemental boiling point:

Atomic radius. Angstrom.

Ionic radius: angstroms.

Covalent radius: Angstroms.

Modulus of bulk elasticity.

GPA: Enthalpy of Atomization: KJ Mol @25: 352 Heat Capacity: J (Mol· K):

Electrical conductivity: 10-6 (cm·

Thermal conductivity. w/（m·k）：

Heat of Fusion: (kJ mol):

Heat of vaporization: (kJ mol) :

The amount of elements in the universe: (ppm):

Atomic volume: (cubic centimeters mol) :

The properties of a substance that do not need to undergo chemical changes are called physical properties, which usually include the color, state, odor, hardness, melting point, boiling point, density, etc. of the substance. When the external conditions change, the properties of the substance will also change, so the conditions should be indicated when describing the properties of the substance.

1. The symbol represents sum, the pronunciation is sigma, and the English meaning is sum, summation, which is and.

Formula calculation: Indicates the number of start and stop. For example, the lower i=2 and the upper number 10 indicate that it is from 2 to 10.

For example, 10 (2i+1) means the sum formula: (2*2+1)+(2*3+1)+(2*4+1)+2*10+1)=222。

The 2i+1 in the formula i=2 is the general term formula ai of the sequence, i is the ordinal number of the terms, i=2 means that the calculation starts from the second term of the sequence {2i+1}, and the top 10 is the cut-off of the 10 terms.

2. Usage:

where i represents the lower bound, n represents the upper bound, and k takes the number from i until n, all of which add up.

i can also be expressed in this way, indicating that i is summed, and i is a variable.

Basic Information. In mathematics, we use as a summation symbol; In lowercase letters, the standard deviation is denoted by .

In physics, we use its lowercase letters to denote areal density. (Correspondingly, the volume density is denoted and the line density is denoted by the linear density). Areal density is the mass per unit area of a substance of specified thickness in terms of engineering materials.

In chemistry, we use its lowercase letter to denote a type of covalent bond. A covalent bond formed by the overlap of two atomic orbitals along the axis of symmetry of the first part of the orbital, resulting in an increased probability of electrons appearing between the nuclei, is called a bond. The key belongs to the localized bond, which can be a general covalent loss bond or a combustible covalent covalent bond.

A single bond in general is a key.

Physical Properties:

State of matter] solid, radioactive.

Melting Point】 k(27).

Boiling point] 950 k(677).

Molar volume] No data.

Heat of vaporization] No data.

Heat of Fusion] No data.

Vapor pressure] no data.

Speed of sound] No data.

Chemistry: Due to nuclear instability, FR-223 has a maximum half-life of only 21 minutes. Its chemical properties can only be studied in trace ranges. It is the heaviest alkali metal element and the most unstable alkali metal.

Francium is chemically active, and exposure to air will produce francium oxide (FR2O) and francium nitride (FR3N) (francium is currently the most theoretically metallic element, all francium salts are water-soluble, and francium hydroxide is also the theoretically most alkaline hydroxide (stable francium hydroxide cannot be prepared at present). Due to its radioactive nature and extremely active chemical reactions, pure francium has not been made so far. Francium is the most unstable natural element:

Its most stable isotope, francium-223, has a maximum half-life of only 22 minutes. In contrast, astatine, the second most unstable element in nature, has a maximum half-life of hours, in contrast, francium is the less stable element among the elements. Francium is an alkali metal that is chemically similar to cesium.

The melting point of francium has been purportedly calculated to be approximately 27 (80,300 K).

Summary. In physics, it means and, and with.

What does it mean in physics.

In physics, it means and, and with.

Physics is the natural science that studies the structure of matter, the interaction of matter, and the laws of motion. As a leading discipline of natural science, physics studies the most basic forms and laws of motion of all matter, from the universe to elementary particles, so it has become the research foundation of other natural science disciplines. Physics is the study of the most general laws of motion of matter and the basic structure of matter.

As a leading discipline in the natural sciences, physics studies the most basic forms and laws of motion of all matter, from the universe to elementary particles, and thus becomes the research foundation of other natural science disciplines.

Physics focuses on the study of matter, energy, space, and time, and especially their respective properties and interrelationships with each other. Physics is the knowledge of the laws of nature; More broadly, physics explores the analysis of phenomena that occur in nature in order to understand their rules.

The smaller the time constant, the faster the circuit responds to change, and vice versa.

The time constant denotes the constant of the time course of the transition reaction. It refers to the time it takes for the physical quantity to decay from the maximum value to 1 e of the maximum value. For an exponentially decaying quantity, the time required for its amplitude to decay to 1 e times is called the time constant.

It's just a symbol that can mean different things.

Such as: the half-life of the decay of the atomic nucleus, the time constant, etc.

Time constant.

Characterize the physical quantity of how fast or slow the response is during the transient process of the circuit. It has a time dimension. The smaller the time constant of the circuit, the faster its response changes, and vice versa.

t in physics refers to the amount of temperature change.

In physics, it is often used as a variable.

The prefix is used to indicate the amount of change in the variable, such as: t (time change), t (temperature change), x (displacement change), v (speed change), and so on.

Another example: in the heat of physics, the formula for calculating the heat absorbed or emitted by an object during heat absorption or heat release is q=cm t(c represents the specific heat capacity of the substance, m represents the mass of the substance, and t represents the change in temperature, that is, the absolute value of the temperature change: t=|t1-t0|）。

Is it v2=v1+a* t? The t in this area refers to the time difference, which is t2-t1.

In fact, the appearance of this symbol is generally a sign of difference, for example, the velocity change v is v2-v1, the temperature change t, and so on.

The distinction between t and t is not very strict in many cases, the temperature is t, and the time is sometimes uppercase and sometimes lowercase.

It is one of the physical quantities that describe the speed of circular motion.

The definition is: =t is the central angle. The unit is rad s, which is commonly calculated:

2 t t is the period. The unit here is also the chain system between rad s angular velocity , linear velocity v, and radius of circular motion r: =v r The conversion of the unit in this formula is as follows:

v Guess the return of the grandson r=(δl δt) r=(δl r) δt where (δl r) = δ unit is radians.

So the unit of =v r is rad s