A (a) is a pure substance that cant be broken down into simpler substances by chemical or physical means

a) element

b) mineral

c) chemical

d) atom

What is the relative mass of an electron? A. 1/1840 the mass of an electron B. 1/1840 the mass of a neuron + proton C. 1840 the mass of a C-12 atom D. 1/1840 the mass of an alpha particle The answer is A.

Which of the following is equal to 3.5 liters?

Why could some minerals be similar in color yet completely different in composition?

Upon heating a sample of NiCl2•6H2O, a sample originally weighing 3.5 g yields an anhydrous salt residue weighing 2.1g. What is the percent by mass of water in the hydrate?

Conduction, convection, radiation

Carbonic acid (H2CO3) does not dissortate 100 percent in water. What type of substance is it? weak acid Strong base strong acid weak base

The standard enthapy of combustion of solid urea co (nh2) 2 is - 632kjmol-1 at 298k

What happens to an isotopes during radioactive

Why does the effective nuclear charge increase across a row of the periodic table?

Iodine-131 decays to form xenon-131. the half-life of this reaction is 8.07 days. from a 200-g sample of iodine-131, how much of the sample is xenon-131 after 16.14 days?