A chemical equation is balanced by changing or adding

a.

chemical symbols.

c.

numbers in front of molecules.

b.

subscripts after atoms.

d.

reactants in the product.

What is magnetization?

Carbon atoms have four valence electrons. are they likely to react with other atoms, and why or why not?

The products obtained by cracking an alkane, X, are methane, ethene and propene. The mole fraction of ethene in the products is 0.5. What is the identity of X?. A C6H14. B C8H18. C C9H20. D C11H24.

What is the density of a crayon

Which statement describes acids? Acids dissolve in water to produce a solution that tastes bitter. Acids dissolve in water to produce a solution that reacts with metals to produce H2 gas.

He substance, cocl2, is useful as a humidity indicator because it changes from pale blue to pink as it gains water from moist air. What is its name?

The weighted average atomic mass of an element depends upon the a. relative abundance of protons in the element b. mass and relative abundance of each isotope of that element c. mass and relative abundance of each neutron of that element d.

What part of an atom do we change for isotopes

The Safe Drinking Water Act (SDWA) sets a limit for mercury-a toxin to the central nervous system-at 0.002 mg/L. Water suppliers must periodically test their water to ensure that mercury levels do not exceed 0.002 mg/L.

The smallest unit of an element is a blank