If an element is very reactive then it will will react with other elements to form compounds in nature
not be found in its pure form in nature
all of the above are true
will have to be mined as another substance and converted into its pure form in order for humans to use it

During trial 2, what allowed you to determine that aluminum was the limiting reactant? check all that apply. all of the copper dissolved. all of the aluminum dissolved. the solution turned clear. the number of grams of copper(ii) chloride used in the reaction was greater than the number of grams of aluminum. the molar ratio of copper(ii) chloride to aluminum was greater than 3: 2, the equation’s molar ratio.

The covalent compound acetylene, which is the fuel of the oxyacetylene torch used by welders, has the molecular formula c2h2. the covalent compound benzene, a commercial solvent, has the molecular formula c6h6 each of these covalent compounds contains carbon and hydrogen atoms in a one-to-one ratio. would it be correct to write the chemical formulas of each as ch? explain.

Consider hydrogen in an excited state n = 5n=5 that emits photons to reach the ground state. there are various possible transitions other than straight to the ground state that can occur; for example, it can drop to the n = 3n=3 state followed by the n = 3n=3 to the ground state transition. which of the possible transitions will result in the emission of a photon in the visible region?