In which orbitals would the valence electrons for selenium (Se) be placed?

A. s orbital and f orbital

B. s orbital only

C. s orbital and p orbital

D. d orbital only

All measurements have some degree of uncertainty. True False

Which of the following reactions have a positive ΔSrxn? Check all that apply. 2A (g) + B (s) - -> 3C (g) 2A (g) + B (g) - -> C (g) A (g) + B (g) - ->C (g) 2A (g) + 2B (g) - ->5C (g)

In the ground state, an atom of each of the elements in Group 2 has a different 1. oxidation state 2. first ionization energy 3. number of valence electrons 4. number of electrons in the first shell

Sodium (Na) has 11 protons and 12 neutrons. What is its isotope notation? A. Na-11 O B. Na-12 C. Na-23 D. Na-34

A. How many hydrogen atoms are on the Reactants side?

How is the way a mixture is combined different from how a compound is combined?

Consider n2 (g) + 3h2 (g) →→ 2nh3 (g). what is the mass of nitrogen gas required to react with 0.129 g h2?

Write a sentence that uses the words "mass extinction" correctly

Which description is not a property of an acid? A turns litmus paper red B bitter taste C corrosive D dissolve metals

Concerning the 10.0 mL of 0.50 M NaCl diluted to 100 mL of solution: When a solution is diluted, does the dilution change the number of grams dissolved? yes no