Helium was discovered in 1868.
the formula of the compound that is formed between chlorine and calcium is CaCl2
explanation
chlorine (non metal) react with Calcium ( a metal) to form an ionic compound CaCl2
Ionic compound is formed when metal loses electrons to form cation ( a positively charged ion) while non metal gains electrons to form anion ( a negatively charged ion)
An ionic compound is formed when calcium metal(Ca) loses two electron to form Ca2+ cation , while 2 chlorine atom gain one electron each to form cl- anions.
- when writing down the formula of ionic compound cation symbol is written first followed by anion symbol.
Therefore the formula of ionic compound formed between chlorine and calcium is CaCl2
Explanation:
Different atoms binds their outermost shell electrons with different amount of energy.
The amount of energy required to remove an electron from an atom is the ionization energy.
- Ionization energy measures the readiness of an atom to lose electrons.
- From the given problem, we can infer that in group O the ionization energy decreases down the group.
- Helium has the highest ionization energy.
- Down a group on the periodic table, ionization energy decrease because:
- atomic radii increases down the group.
- there is an increasing shielding/screening effect of inner shell electrons on the outermost shell electrons.
Learn more:
Ionization energy brainly.com/question/2153804
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Answer:
Under the earth's surface, rocks melt, metamorphize, and crystalize.
Explanation:
Metamorphic and Igneous rocks are basically dependant on the heat/pressure of the environment under the surface :) Melting, metamorphosing and crystallization all occur under earth's surface.
Answer:
Length of a rectangle whose width is 4 inches is
<u>6 inches</u>
Explanation:
Ratio of length to its width is 3 to 2
Let length = L
Let Width = B
L: B = 3 : 2 (given)

Width ,B = 4
Insert B in above equation


cross multiply,

L = 6 inches
Conversion(if required) ,
1 inch = 2.54 cm
6 inch = 2.54 (6)
L = 15.24 cm