Is it always possible to identify something as an element compound pure substance or mixture just by looking at it

The nucleus of an atom can have either a positive or negative charge

For a star of sun-like mass, what is the last stage of the nuclear fusion? a. hydrogen to helium b. helium to carbon and oxygen c. fusion goes all the way up to iron. d. carbon to magnesium

Dissolving sugar in water is a chemical change. True False

If the water in a bathtub and a teacup are the same temperature, how do the amounts of their thermal energy compare? A. They both have the same amount of thermal energy. B. The teacup has more thermal energy. C.

Al + 02 = A1203 1. What coefficient values will balance the reaction shown above? (Show your work for each set of coefficients.) A 2,3, 2 B 2, 1, 1 C 4,3,2 D 4,2,3

A geneticist has discovered a new compound that is made up of a small number of identical subunits. The subunits are joined end to end in long chains. Based on this information, what best can be concluded about these subunits? A. They are ketones. B.

What kind of cell keep dirt off your body's organs

How could one rapidly separate red #40 from zinc oxide? indicate every step.

What is the KE of 750 kg car moving at 25 m/s?

Which of the following is an extensive physical property? viscosity color mass density