The carbon-magnesium bond in a Grignard reagent is covalent and highly-polarized such that the carbon is negatively charged. Which of the following statements can be used to describe the Grignard carbanion? Select all that apply.
1. Grignard reagents are weak bases
2. Grignard reagents are weak nucleophiles
3. Grignard reagents are strong bases
4. Grignard reagents are strong nucleophiles