An element's atomic number is 87. how many protons would an atom of this element have

The gas arsine, AsH3, decomposes as follows. 2 AsH3 (g) 2 As (s) 3 H2 (g) In an experiment at a certain temperature, pure AsH3 (g) was placed in an empty, rigid, sealed flask at a pressure of 392.0 torr.

A balloon is floating around outside your window. The temperature outside is - 5 ∘C, and the air pressure is 0.700 atm. Your neighbor, who released the balloon, tells you that he filled it with 4.80 moles of gas.

The formula of a salt is XCl2. The X-ion in this salt has 28 electrons. The metal X is

Which list of elements contains two metalloids? (1) Si, Ge, Po, Pb (3) Si, P, S, Cl (2) As, Bi, Br, Kr (4) Po, Sb, I, Xe

What are 3 acids and 3 bases and list an industrial or household use of each.

Which statement best explains why the overall charge on an atom is zero?

The outermost layer of the atmosphere is what

Choose the correct statement regarding the behavior of water. a. The water phase with the highest heat capacity is gas vapor. b. The liquid-to-vapor phase change of water requires less energy than the ice-to-liquid phase change. c.

What is the bond angle for a trigonal pyramidal molecule?

Gaseous methane (CH4) reacts with gaseous oxygen gas (O2) to produce gaseous carbon dioxide (CO2) and gaseous water (H2O) If 0.391 g of carbon dioxide is produced from the reaction of 0.16 g of methane and 0.