How many moles are in 2.91 × 10²² atoms of He?

Asubstance is a good conductor of electricity which of the following best explains a probable position of the substance in a periodic table

Ajar contains a certain substance. which observation would show that the substance must be either a solid or a liquid?

Which statement explains which component is likely to be more powerful in explaining a scientific phenomenon? a) component c, because a theory is often passed on possibility and not certainty b) component d, because a hypothesis is often based on possibility not certainty c) component c, because the ability to explain several occurrences in the natural world is a characteristic of a hypothesis d) component d, because the ability to explain several occurrences in the natural world is a characteristic of a theory