not all atoms can be bonded together at random and form stable configurations. use the periodic table above to determine which of the following molecules are stable
MgO
PH3
CaBr
NaF2
To determine the stability of the given molecules, we need to consider the properties and valence electrons of each element.
1. MgO:
Mg is in Group 2 of the periodic table and has 2 valence electrons, while O is in Group 6 and has 6 valence electrons. Mg tends to lose its 2 valence electrons, while O tends to gain 2 electrons to achieve a stable octet configuration. Therefore, MgO can form a stable ionic bond, where Mg loses its 2 electrons to O, forming Mg2+ and O2- ions, resulting in the stable compound magnesium oxide (MgO).
2. PH3:
P is in Group 15 and has 5 valence electrons, while H is in Group 1 and has 1 valence electron. P tends to gain 3 electrons to achieve a stable octet configuration, while each H can share 1 electron with P. However, PH3 is not stable because it violates the octet rule for the central atom P, as it has 8 electrons (3 bonding pairs and a lone pair). Therefore, PH3 is not a stable molecule.
3. CaBr:
Ca is in Group 2 and has 2 valence electrons, while Br is in Group 17 and has 7 valence electrons. Ca tends to lose 2 electrons, while Br tends to gain 1 electron to achieve a stable octet configuration. Therefore, CaBr can form a stable ionic bond, where Ca loses its 2 electrons to Br, forming Ca2+ and Br- ions, resulting in the stable compound calcium bromide (CaBr2).
4. NaF2:
Na is in Group 1 and has 1 valence electron, while F is in Group 17 and has 7 valence electrons. Na tends to lose 1 electron, while F tends to gain 1 electron to achieve a stable octet configuration. However, NaF2 violates the octet rule for F, as it would have more than 8 electrons (10 electrons in this case on the central F atom). Therefore, NaF2 is not a stable molecule.
In summary, the stable molecules among the given options are:
- MgO (magnesium oxide)
- CaBr (calcium bromide)
Your said CaBr2 , from Ca ++ and 2 Br -
but what about the CaBr that was asked? Br -2 ????
Apologies for the confusion earlier. You are correct, the formula for calcium bromide (CaBr) indicates the presence of one bromide ion (Br-) and one calcium ion (Ca2+). The electron configuration for a stable CaBr molecule would involve the transfer of one electron from calcium to bromine. Therefore, CaBr can still form a stable ionic bond and is a stable molecule.
I think Ca Br2 is stable
I do not think Ca Br is stable