An order for ampicillin is 45 mg/kg of body mass. Calculate the dosage of ampicillin in g/lb of body weight. Express the dosage in g/lb to two significant figures.
Could anybody explain how to do this?

0.020g/lb

Explanation:

We start off with 45 mg/kg.

Let's convert the mg to g first to get half the units correct.

1g = 1000mg

Therefore 45mg = 0.045g.

Now we're at 0.045g/kg.

Next we need to convert the kg to lbs.

1 kg = 2.20462262 lbs.

therefore we need to divide 0.045 by 2.20462... to get g/lbs

This gives 0.02041165667 g/lb.

We need this to 2SF, so round to 0.020g/lb

alkaline metals are lithium, sodium, rubidium, potassium, cesium and francium.

alkali metals have electronegativity from 0.7 to 1, lowest in periodic table of elements, which means that alkali metals (i group in periodic table) has positive oxidation number in compounds.

electronegativity is a chemical property that describes the tendency of an atom to attract a shared pair of electrons towards itself.

alkaline metals (far left in main group) have lowest ionizations energy and easy remove valence electrons,

for example, potassium is the alkali metal and has a single valence electron in the outer electron shell.

electron configuration of potassium is: ₁₉k 1s²2s²2p⁶3s²3p⁶4s¹.

they can not exist alone in nature, because they are very reactive.