Why do scientists have to make an experiment

Can you identify the 4th most abundant element in the universe?

Right now it is soluble. that's why it is dissolved in the water. which of the following can I add to make it soluble NaNo3. BaNO3. AgNO3

How are solutions heated in a small 3 mL test tube

In water, HCN is a weak acid with pKa = 9.6. a. Calculate the the Ka and the [H+] in a 0.15 M solution of HCN. b.

Which one of the following statements is true? Both chemical and physical changes can involve a change in appearance. Neither chemical nor physical changes involve a change in appearance. Only physical changes involve a change in appearance.

The organisms living together in a community are interdependent upon one another. Look at the food web below. In which of the following ways is a puffin dependent upon salmon? A. Puffins have a commensalistic relationship with salmon. B.

2) Which of the following is a true statement? A: All the atoms of an element must be identical. B: Compounds may be separated by physical means. C: Mixtures may not be separated. D: Homogeneous is one type of compound.

How to tell the difference between ionic and covalent bonding?

The combustion of propane may be described by the chemical equation C3H8 (g) + 5O2 (g) ⟶3CO2 (g) + 4H2O (g) C3H8 (g) + 5O2 (g) ⟶3CO2 (g) + 4H2O (g) How many grams of O2 (g) O2 (g) are needed to completely burn 83.3 g C3H8 (g) ?

Was the relationship among temperature, heat, and thermal energy?