A 52.9g sample of brass, which has a specific heat capacity of 0.375·J·g−1°C−1, is put into a calorimeter (see sketch at right) that contains 100.0g of water. The temperature of the water starts off at 15.0°C. When the temperature of the water stops changing it's 18.4°C. The pressure remains constant at 1 atm. Calculate the initial temperature of the brass sample. Be sure your answer is rounded to 2 significant digits.

T₁ = 90°C

Explanation:

Let system 1 => brass sample & system 2 => water

∑q = 0 = q₁ + q₂ =  (mcΔT)₁ + (mcΔT)₂

= [(52.9g)(0.375j/g°C)(18.4°C - T₁)]₁ + [(100.0g)(4.184j/g°C)(18.4°C - 15°C)]₂ = 0

=> 19.83(18.4°C - T₁) + 1423 = 0 => 365 - 19.83T₁ + 1423 = 0

=>19.83T₁ = 1788 => T₁ = (1788/19.83)°C = 90°C

"among the transition metal elements, manganese and zinc have a slight lowering of electronegativities. the reason behind this is that the nuclear charges of these elements are slightly weaker than the other transition metal elements due to the way their valence electrons are filled up. both manganese and zinc have their valence electrons filled up to the 4th shell with 1 pair of electrons (4s2) completely occupying it. although the electrons in the 3rd shell (3d) are yet to be paired since the outer most shell is filled up, the ability of the nucleus to attract electrons is lessened. hence,   the electronegativity (or the ability to attract electrons) is lessened."

if you mean hydrogen and oxygen then water is the product