Which of these pairs of elements have the same number of valence electrons?

phosphorus (P) and chlorine (Cl)

berylium (Be) and calcium (Ca)

chlorine (Cl) and helium (He)

oxygen (O) and carbon (C)

The temperature of 500.0 g of water contained in a calorimeter increased from 20.0 °C to 50.0 °C when 5.00 g of fuel was burned to completion. What is the ΔH of this combustion reaction? (The specific heat of water is 4.

How do you fart without it stinking

What is the change in heat energy when 64.82 g of aluminum metal at 100.0oC is cooled to 82.0 °C? The specific heat of aluminum is 0.897 J / g °C.

An atom of hydrogen-2 contains one proton, one neutron, and one electron. Which particle (s) identify the atom as hydrogen? the electron the neutron the proton the proton and the neutron

How to determine whether an element is paramagnetic or diamagnetic?

The definition of volume is? a) width*height b) the space occupied by mass c) the space occupied by a liquid d) the mass of liquid required to fill a container

What is the empirical formula of a substance that is 53.5% C, 15.5% H, 31.1% N?

What is the lowest layer of the atmosphere and what is its highest altitude?

An atom that has 84 protons and 86 neutrons undergoes a reaction. At the end of the reaction, it has 82 protons and 84 neutrons. What happened to the atom?

A compound of material formed by a chemical is known as?