Which one of these exhibits a notochord at some stages of its development?

A brittle star

A tapeworm

A cat

A hydra

A compound is 42% sodium, 19% phosphorus, and 39% oxygen by mass. What is the empirical formula of this compound? Na3PO4 NaPO Na9P4O8 Na4P3O

Most of high-level hazardous radiation associated with nuclear energy is a result of Waste materials Mining and transportation of radioactive fuels Radiation emissions from nuclear sites All of the above

Which equation represents a neutralization reaction? a. LiOH (aq) + HBr (aq) - >LiBr (aq) + H20 (1) b. 2HCl (aq) + Zn (s) - > ZnCl2 (aq) + H2 (g) c. H2CO3 (0) - -> H2O + CO2 (g) d. 2NaHCO3 (s) - > Na2CO3 (s) + H2O (g) + CO2 (g)

A laboratory technician needs to make a 108 -liter batch of a 20 % acid solution. how can the laboratory technician combine a batch of an acid solution that is pure acid with another that is 10 % to get the desired concentration?

Which of the following statements is true? a) Processes are spontaneous because they occur at an observable rate. b) Spontaneity can depend on the temperature.

Name 4 common chemical properties of matter

Why is photosynthesis so important to plants, and can't animals use it?

One way the government of Kim Jong-il controls the lives of the people who live in North Korea is by a. requiring every citizen to vote. b. controlling information its people receive from the outside world. c. enforcing free trade with other nations.

Give reasons 1) copper utensils and sheets become blackish after some days

Predict the spontaneity of a reaction (and the temperature dependence of the spontaneity) for each possible combination of signs for? H and? S (for the system).