Why did mendeleev leave blanks in his early version of the periodic table?

What do all members of the swine species have in common

Magnesium oxide (MgO) forms when the metal burns in air. (a) If 1-25 9 of MgO contains 0.754 g of Mg, what is the mass ratio of magnesium to oxide? (b) How many grams of Mg are in 534 g of MgO?

Two___ of the element sodium combine with one___ of the element chlorine to form the ___ sodium chloride

0.100g of Cu (OH) 2 was added to a beaker which was filled to the 3.00L mark with water. what is the pOH of the solution

Which type of soil holds the least water

What is the total pressure when 0.400 g of H2, 2.00 g of N2, and 10.5 g of CO2 are injected into a 10.0 liter flask at 273 K?

The balanced chemical equation for the combustion of methane is: CH4 (g) + 2 O2 (g) → CO2 (g) + 2 H2O (g) Which of the following statements concerning this chemical equation is/are correct? 1.

In one kind of nuclear reaction, two nuclei fuse, or join together, to form a larger nucleus. This kind of reaction happens only at very high pressures. Explain why such high pressures are necessary to cause these reactions to occur.

Check the approach to obtain the correct conversion equation. Use the temperature in °F to find the temperature in °C. °C

What is the volume of a gas at 50.0 Celsius and. 80 atm if there are. 75 moles of a gas present?