How do they know the valence of an element if they have never seen it?

Which of these statements is correct? Eukaryotic cells do not have ribosomes. Eukaryotic cells do not have chloroplasts. Prokaryotic cells do not have a cell wall. Prokaryotic cells do not have a nucleus.

What is 0.001012 in scientific notation

The density of piece of wood will remain the same regardless of its temperature true or false

Treatment of an alpha, beta-unsaturated ketone with basic aqueous hydrogen peroxide yields an epoxy ketone. the reaction is specific to unsaturated ketones; isolated alkene double bonds do not react.

How many electrons would be exchanged from lithium and fluorine

Collagen is made of fibers and is found in tendons and cartilage. Collagen contributes to meat toughness and is, therefore, an example of which type of protein?

1. Why does CH30 evaporate faster than water?

How does concentration affect our daily lives in science?

How many nitrogen atoms are in 2.79 mo. of NH3

What is the chemical formula for polysaccharide?