What are variables that do not change in a experiment called

If 224 g of iron reacts with oxygen, forming 320 g of iron oxide, how much iron oxide would 112 g of iron produce?

Which phrase is an example of what electrostatic forces hold together? A. Fr atoms and localized in iron B. He atoms in helium gas C. oxygen and hydrogen atoms in OH- D. Na + and Br - in NaBr I'm not sure about this one.

Describe Thomson's Cathode Ray experiment and Rutherford's Gold Experiment, including the observed results that caused the scientific community to accept changes to Dalton's original model of the atom.

45 grams of NaOH to moles

Which of the following states an important result of Rutherford's gold-foil experiment? A. Atoms have mass. B. Electrons have a negative charge C. Neutrons are uncharged particles D. The atom is mostly empty space

An excess of NiCO3, 12 g, was added to 40cm cube of sulpheric acid, 2.0 mol/dm cube. The unreacted nickel carbonate was filtered out and the filtrate evaporated to optain the crystals.

Under what condition is decompostion the fastest? Under what condition is it the slowest?

Which compound has the strongest hydrogen bonding between its molecules? 1. HBr 2. HF 3. HCl 4. HI

Arrange the following bonds in order of increasing polarity: O-H, C-H, F-H, H-H A) O-H B) C-H<0-H C) H-H D) C-H E) HH

How fast do p waves travel?