Which statement describes a physical change?

A.

Sodium metal reacts explosively with oxygen.

B.

Lead is heated and becomes more viscous.

C.

Calcium is added to acid and hydrogen gas is produced.

D.

Iron combines with oxygen to form rust.

What observations will you look for to determine if a metal undergoes reaction?

Which of the following is formed from erosion A) lake B) delta C) stream D) aquifer

When magnesium combines with sulfur to form magnesium sulfide, it is oxidized to Mg2+. Which statement is true about this reaction? A. It involves gain of electrons. B. It involves loss of electrons. C. It involves loss of oxygen. D.

2al (c2h3o2) 3 + 3baso4 → al2 (so4) 3 + 3ba (c2h3o2) 2 which type of chemical reaction does this equation represent? f synthesis g neutralization h oxidation-reduction j double-replacement

How many milliliters of a 20% solution should be added to 60 ml of a 40% solution to obtain a 35% solution?

Oceans make the temperaturs of nearby land more extreme ... True or false

In a chemical reaction, atoms are created/rearranged. The atom are joined together in the same/different arrangements after the reaction. The total number of each type of atom is greater/less/The same after the reaction.

Is dry ice subliming, endothermic or exothermic?

An atom that gains or loses an electron has a net electric charge and is called a/n A. ion. B. electron. C. proton. D. neutron.

Write the name of the following compound NH^3