A 3.0 mole sample of KBrOz was decomposed according to the following

equation. How many moles of O2 are formed? *

2KBrO3 → 2KBr + 302

A fossilized leaf contains 24% of its normal amount of carbon 14. how old is the fossil (to the nearest year) ? use 5600 years as the half-life of carbon 14.

What kinds of scientific investagations involve making observations

Why is methane, CH4, a nonpolar compound? It does not have covalent bonds. Each covalent H bond is nonpolar. The nonpolar bonds are distributed evenly around the carbon atom. It forms a symmetrical planar triangle.

Which was a testable idea that J. J. Thomson developed through his experiments? Atoms are the most important substances in the universe. It is impossible to divide an atom into smaller parts. There are electrically neutral particles inside atoms.

A scientist compares two samples of white powder. One powder was present at the beginning of an experiment. The other powder was present at the end. She wants to determine whether a chemical reaction has occurred.

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

What will most likely happen when a warmer air mass exists above a polar ice sheet? The temperature of the ice sheet will be lowered. Heat will be transferred from the air mass to the ice. The air mass will exert high pressure and rise upwards.

A 2.00 L sample of gas at 35 C is to be heated at constant pressure until it reaches a volume of 5.25 L. To what Kelvin temperature must this sample be heated?

Of the following reactions, which one produces oxygen gas? Fermentation Anaerobic respiration Aerobic respiration Photosynthesis

Describe the electrodes in this iron-copper galvanic cell.