Determinaţi numărul atomic pentru elemetele situate în: a) grupa a II-a A, perioada 2;
b) grupaa V-a A, perioada 3;
c) grupa a II -a A, periada 4;
d) grupa a VI-a A, perioada 3.

150.0 grams of asf3 were reacted with 180.0 g of ccl4 to produce ascl3 and ccl2f2. if the actual yield of ccl2f2 was 127 g, what is the percent yield?

Calculate the standard enthalpy of formation of liquid methanol, ch3oh(l), using the following information: c(graphite) + o2 latex: \longrightarrow ⟶ co2(g) latex: \delta δ h° = –393.5 kj/mol h2(g) + o2 latex: \longrightarrow ⟶ h2o(l) latex: \delta δ h° = –285.8 kj/mol ch3oh(l) + o2(g) latex: \longrightarrow ⟶ co2(g) + 2h2o(l) latex: \delta δ h° = –726.4 kj/mol

What does the field of thermodynamics relate to a-changes in nuclear reactions b- changes in energy in systems c changes in molecular structure d changes in atomic properties