How would one know if something is an element?

How many neutrons make up one of these potassium atoms

The mechanical advantage of a door knob that allows you to move a boli 0.01 m by moving the handle 0.50 m is A. 0.05 B. 0.50 C. 5.0 D. 50

How many molecules are in 189.5 grams of no2?

Explain how cobalt-60 and cobalt - 59 can be the same element but have different mass numbers

What is the molarity of a solution prepared by dissolving 33.4 g of sodium chloride in some water and then diluting the solution to a volume of 300.00 mL?

Gasohol is a fuel containing ethanol (c2h6o) that burns in oxygen (o2) to give carbon dioxide and water.

Consider a neutral atom with 30 protons and 32 neurons. What is the atomic number of the element?

Find the molarity and molality of 37.0 wt% Hcl. Assume the density of the acid is 1.19g/ml

Which excerpt from "Bone Detective" best shows that Diane France is recognized as an expert in her line of work? But, once again, she was able to produce an amazingly detailed impression.

Blank of water is a physical change because boiling the water is blank from a liquid to a gas