Barium, Beryllium, Radium, and Calcium.
<h3>Explanation</h3>
All four metal elements (Ba, Be, Ra, and Ca) are found in group 2 of a modern periodic table. By periodicity, they have similar chemical properties.
Shared properties likely include:
- Softness. With only two valence electrons per atom, the four elements form weak metallic bonds. Their pure forms are thus easy to shape and cut.
- High reactivity. Group 2 "alkaline-earth" metals are only two electrons away from ideal gas electron configurations. They lose electrons more readily than most transition metals such as iron and copper do. Group 2 metals tarnish easily in the earth atmosphere, and reacts readily with water to produce hydrogen and a base- hence the name "alkaline."
This question is incomplete, the complete question is;
Tonksite is a solid at 300.00K. At 300.00 K its enthalpy of sublimation is 66.00 kJ/mol. The sublimation pressure at 300.00 K is 5.00 × 10⁻⁴ atm
Calculate the sublimation pressure of the solid at the melting point of 400.00 K assuming that the enthalpy of sublimation is not a function of temperature.
Answer: the sublimation pressure of the solid at the melting point is 0.3727 atm
Explanation:
Given that;
T1 = 300 K
T2 = 400 K
H_sub = 66 kJ/mol = 66000 J/mol
P1 = 5.00 × 10⁻⁴ atm
p2 = ?
now using the expression
log( p2 / 5.00 × 10⁻⁴ ) = (H_sub / R × 2.303 ) (( T2 - T1) / T1T2)
now we substitute of given values into the expression
log(p2/p1) = (66000 / 8.314 × 2.303 ) (( 400 - 300) / 300 × 400 )
p2 = 0.3727 atm
therefore the sublimation pressure of the solid at the melting point is 0.3727 atm
Answer:
A)P5010
Explanation:
Penta- means 5 and deca/deco- means 10
<span>A cation is an atom that loses a valence electron. When a valence electron is released there is one electron less to create a repulsive force. The loss of a repulsive force will allow the atom to pull tighter together. An anion would therefore be larger in size due to increased repulsion of the valence electrons.</span>
Here's link to the answer:
tinyurl.com/wpazsebu
