Meningioma; Synonyms: Meningeal tumor: A contrast-enhanced CT scan of the brain, demonstrating the appearance of a meningioma: Specialty: Neurosurgery: Symptoms: None, seizures, dementia, trouble talking, vision problems, one sided weakness: Usual onset: Adults: Types: Grade I, II, III: Risk factors: Ionizing radiation, family history: Diagnostic method
A polar covalent bond shares electrons unequally. Because of this unequal sharing, one end of the molecule is slightly positive, and the other end slightly negative. Edit
In ionic bonds, one atom donates its valence electrons to another atom in the formation of the bond. Covalent bonds form when atoms are able to share valence electrons. However, if the attraction for electrons is greater in one atom than the other, the electrons tend to orbit the stronger atom. As a result, the molecule tends to have a positive end and a negative end and the bond is a polar covalent bond. Water forms polar molecules. Metal atoms join together through metallic bonds.