Answer:
element
Explanation:
elements consist of pure substances
carbon atoms form 2 bonds with sharing valence electrons
The answer is <span>non-biodegradable and subject to bioaccumulation and/or bioamplification.
DDT (dichlorodiphenyltrichloroethane) is persistent, non-degradable insecticide and organic pollutant readily accumulated to soils and consequently affects organisms.
DDE (</span><span>dichlorodiphenyldichloroethylene) is non-degradable pesticide toxic to birds at the first place.
PCBs (polychlorinated biphenyls) are non-degradable organic compounds very toxic to the environment.
PBDEs (polybrominated diphenyl ethers) are non-degradable compounds very toxic to environment, even able to affect brains of animals in the development period.</span>
Pluto is a dwarf planet, but one of the largest known members, in the Kuiper belt.
The Kuiper Belt extends between 30 AU and 55 AU from the Sun
(1 AU = 1.5 × 10^8 km = distance from Earth to Sun).
Pluto's orbit is highly elliptical. It ranges from 30 AU to 50 AU. When Pluto is closest to the Sun, it is inside the orbit of Neptune (30 AU).
Astronomers class Pluto as a <em>resonant Kuiper belt object</em> (KBO). Because it gets so close to Neptune, its orbit is in <em>resonance</em> with that of Neptune. Pluto makes two orbits for every three of Neptune.
Answer:
element having 2+ valence electrons can transfer its more than one electron that is 2 electron completely.
Explanation:
- Group IIA have 2+ valency and two electrons in its valance shell.
- Its Electropositivity is high and have the tendency to donate it two electrons.
- Element of IIA form ionic with most electronegative element.
Examples:
Cu²⁺, Mg²⁺, Sr²⁺ are examples having 2+ valance electron
one of the following is examples of element that have 2+ valence electrons
MgCl₂
Atomic number of Magnesium (Mg) is 12
Electronic Configuration of Mg:
1s², 2s², 2p⁶, 3s²
or
K =2
L = 8
M = 2
So, it have to give its 2 electrons to form a stable compound.
Similarly
Chlorine atomic number is 17
Electronic Configuration of Chlorine:
1s², 2s², 2p⁶, 3s², 3p⁵
or
K =2
L = 8
M = 7
So, it have to gain one electrons to form a stable compound and complete its octet.
So,
Two chlorine atom as a molecule gain 2 electrons from Mg²⁺ atom
So one Mg²⁺ and 2 Cl⁻ atoms form an ionic bond
where in this ionic bond Mg²⁺ transfer its 2 valence electron completely and chlorine molecule accept 2 electrons.
Cl-----Mg------Cl
So the Answer is
element having 2+ valence electrons can transfer its more than one electron that is 2 electron completely.
