List two characteristicts that fern, club mosses, and horse tails share

What does x represent in the formula for the compound xcl4?

The alkali metals (group 1) consist of lithium (3), sodium (11), potassium (19), rubidium (37), cesium (55), and francium (87). they are soft, metallic solids with low densities and low melting points. based on the data shown in figure 1, how many valence electrons do alkali metals share?

Which describes fat? a: a carbohydrate that produces energy b: a nucleic acid that directs cell function c: a lipid that stores energy d: a protein that speeds up a chemical reaction