All categories

1 year ago

Chemical element that has atomic number less than 58 and atomic mass greater than 135.6

1 answer:

4 0

A chemical element that has an atomic number less than 58 and an atomic mass greater than 135.6m is barium (atomic no. 56 and atomic mass137.13 ) and lanthanum (atomic no. 57 and atomic mass 135.6).

<h3>Give a brief introduction about Barium and Lanthanum.</h3>

Barium

Barium is an element with the symbol Ba and atomic number 56. It is an alkaline earth metal that is soft and silvery, and it is the fifth element in group 2. Barium is never found in nature as a free element due to its extreme chemical reactivity. Oil well drilling fluid uses barium sulfate as an insoluble ingredient. It is employed as an X-ray radiocontrast agent in a purer form to image the human gastrointestinal tract. Barium compounds that dissolve in water have been employed as rodenticides despite being hazardous.

Lanthanum

Chemical element lanthanum has the atomic number 57 and the symbol La. It is a silvery-white, ductile, soft metal that slowly tarnishes when exposed to air. It serves as the eponym for the group of 15 related elements in the periodic table between lanthanum and lutetium, of which lanthanum is the first and prototype. The rare earth elements traditionally include lanthanum.

Learn more about elements here:-

brainly.com/question/6335008

#SPJ9

You might be interested in

An aqueous solution containing 17.5 g of an unknown molecular (nonelectrolyte) compound in 100.0 g of water has a freezing point

Sonbull [250]

Answer:

molar mass = 180.833 g/mol

Explanation:

mass sln = mass solute + mass solvent

∴ solute: unknown molecular (nonelectrolyte)

∴ solvent: water

∴ mass solute = 17.5 g

∴ mass solvent = 100.0 g = 0.1 Kg

⇒ mass sln = 117.5 g

freezing point:

ΔTc = - Kc×m

∴ ΔTc = -1.8 °C

∴ Kc H2O = 1.86 °C.Kg/mol

∴ m: molality (mol solute/Kg solvent)

⇒ m = ( - 1.8 °C)/( - 1.86 °C.Kg/mol)

⇒ m = 0.9677 mol solute/Kg solvent

molar mass (Mw) [=] g/mol

∴ mol solute = ( m )×(Kg solvent)

⇒ mol solute = ( 0.9677 mol/Kg) × ( 0.100 Kg H2O )

⇒ mol solute = 0.09677 mol

⇒ Mw solute = ( 17.5 g ) / ( 0.09677 mol )

⇒ Mw solute = 180.833 g/mol

6 0

2 years ago

What is the molarity of a solution with 130g of CoCl2 in 1/2 liter? (can you show the steps please)

Elden [556K]

Answer:

Explanation:

M=mol/L

1. Find moles of CoCl2

mass of substance/molar mass = 130/129.833 = 1.001 mol

3. Substitute in molarity equation

M=(1.001/0.5)

M= around 2M

7 0

2 years ago

Which of the following elements is the least reactive metal? Sodium, Rubidium, Chlorine, and Magnesium.

LuckyWell [14K]

First off chlorine is not a metal so you can ignore that one.

Sodium and Rubidium are in group 1 of the periodic table and Magnesium is in group 2.

Group one metals are more reactive than group two because it is harder for the group two metals to lose their 2 valence (outer most) electrons.

As you go down group 1 there is an increase in the reactivity this is because as you go down there is an increase in the atomic radius which leads to more shielding. This weakens the electrostatic forces of attraction making it easier to lose the outermost electrons, therefore they are more reactive.

6 0

2 years ago

An ionic bond forms when atoms blank electrons

8_murik_8 [283]

Answer:

An ionic bond forms when atoms transfer electrons.

Explanation:

Ionic bonds are formed when atoms transfer electrons. (In contrast, covalent bonds are formed when atoms share electrons.)

There's a distinction between the two: when two atoms react to form an ionic bond, one atom would completely lose one electron, while the other would completely gain that electron. The atom that loses the electron becomes a positively-charged ion called a cation, whereas the atom that gains the electron becomes a negatively-charged ion called an anion.

For example, consider the reaction between a sodium $\rm Na$ atom and a chlorine $\rm Cl$ atom: $\rm Na + Cl \to NaCl$ .

When the sodium atom and the chlorine atom encounter, the sodium atom would lose one electron to form a positively-charged sodium ion, $\rm Na^{+}$ . The chlorine atom would gain that electron to form a negatively-charged chlorine ion $\rm Cl^{-}$ .

These two ions will readily attract each other because of the opposite electrostatic charges on them. This electrostatic attraction (between two ions of opposite charges) is an ionic bond.

Overall, it would appear as if the sodium $\rm Na$ atom transferred an electron to the chlorine $\rm Cl$ atom to form an ionic bond.

In contrast, when two atoms react to form a covalent bond, they share electrons without giving any away completely. Therefore, it is possible to break certain covalent bonds apart (using a beam of laser, for example) and obtain neutral atoms.

On the other hand, when an ionic bond was broken, the result would be two charged ions- not necessarily two neutral atoms. The electron transfer could not be reversed by simply breaking the bond.

For example, when table salt $\rm NaCl$ is melted (at a very high temperature,) the ionic bond between the sodium ions and chloride ions would (mostly) be broken. However, doing so would only generate a mixture of $\rm Na^{+}$ and $\rm Cl^{-}$ ions- not sodium and chlorine atoms.

7 0

2 years ago

Can someone help me with problem 21.105? Many thanks!

Reika [66]

The correct answer is 1 to the 3rd power

3 0

2 years ago