Is it easier to identify an unknown metal by such as physical properties as colour, lustre, mass, and volume, or by characteristic physical property such as density? Explain your answer.

Which contains elements with similar properties in the periodic table? A. a period B. a column C. a row

How many nuclei of 238 92 U 92 238 U remain in a rock if the activity registers 290 decays per second? (Note that the half life of Uranium-238 is 4.468x109 years)

Find the enthalpy of neutralization of HCl and NaOH. 87 cm3 of 1.6 mol dm-3 hydrochloric acid was neutralized by 87 cm3 of 1.6 mol dm-3 NaOH. The temperature rose from 298 K to 317.4 K. The specific heat capacity is the same as water, 4.18 J/K g. A.

When pure sodium hydroxide is dissolved in water, heat is evolved. In a laboratory experiment to measure the molar heat of solution of sodium hydroxide, the following procedure was followed. To a calorimeter containing 3.00 * 10^2 g of water at 20.

How many carbon atoms are there in 2.12 molecules of propane? (C3H8)

Two pure elements react to form a compound. One element is an alkali metal, X, and the other element is a halogen, Z. Which of the following is the most valid scientific claim that can be made about the compound? a. It has the formula XZ2 b.

Are protons positive and neutrons neutral

Why might it be useful to determine the elements that a planet or moon is made up of?

Which of these is an example of a solution A Sand stirred in water B Sugar stirred in tea C A glass of water with ice in it D Oil and vinegar in a salad dressing jar

What are properties of colloid