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

A brittle star

A tapeworm

A cat

A hydra

How is a gas formed?

An element x is found to have a mass number of 31 and atomic number of 17. idenrify the group and the period to which it belongs?

Which of the following statements is true about gas particles? The space between them is very small. They repel each other with a strong force. They collide to increase their net kinetic energy. The attractive force between them is very weak.

According to Reference Table N, which radioactive isotope will retain only 1/8 its original radioactive atoms after approximately 43 days? A. gold-198 B. iodine-131 C. phosphorus-32 D. radon-222

Which of the following is a statement of Hess's law? If a reaction is carried out in a series of steps, the ΔH for the reaction will equal the sum of the enthalpy changes for the individual steps.

Is metalloid an insulator

What is a example of a population

Which of the following statements holds true for a chemical change? OA In a chemical change, no new substance is formed. B. In a chemical change, a substance changes its phase. oc. In a chemical change, the molecular structure of a substance changes.

What is the name of the branch of science that specifically studies the conversion of chemical energy to electrical energy and vice versa? biochemistry electrochemistry organic chemistry thermodynamics

What is the symbol for heat