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Questions in chemistry

[Answered] Which represents a balanced nuclear equation? ${ }_{11}^{23} Na \longrightarrow{ }_{12}^{24} Mg +{ }_1^1 H$ ${ }_{11}^{24} Na \longrightarrow{ }_{12}^{24} Mg +{ }_{-1}^0 e$ ${ }_{13}^{24} Al \longrightarrow{ }_{12}^{24} Mg +{ }_{-1}^0 e$ ${ }_{12}^{23} Mg \longrightarrow{ }_{12}^{24} Mg +{ }_0^1 n$

[Answered] Select the correct answer. For heavy elements, what is the ratio of neutrons to protons that predicts a stable nucleus? A. 1:1 B. 1.5:1 C. 2:1 D. 10:5

[Answered] A student combined equal amounts of two solutions. One solution had a pH of 2 and the other had a pH of 12. Which would most likely be the resulting pH? A. 1 B. 3 C. 11

[Answered] The polyatomic ion with the formula CN- is called

[Answered] For a fuel to burn completely, a sufficient quantity of A. oxygen B. pressure C. tension D. vapor must be supplied.

[Answered] Why is photochemical smog typically worse in the summer? A. There is more solar energy to drive photochemical reactions. B. People tend to travel more in the summer. C. Temperature inversions and heat domes drive photochemical reactions. D. Warm temperatures prevent the dissipation of pollutants.

[Answered] Differentiate between electropositivity and electronegativity.

[Answered] Select the correct formula for the polyatomic ion. You can find a list of common polyatomic ions by clicking here. The formula for ammonium carbonate: A. $NH _4 \cdot HCO _3$ B. $NH _4 CO _3$ C. $\left( NH _4\right)_2 CO _3$

[Answered] A scientist wants to determine how many moles of chromium (Cr) would be needed to react completely with 8.22 mol of oxygen $(O_2)$. $2 Cr+O_2 \rightarrow 2 CrO$ How many moles of chromium are needed? $8.22 mol O_2$ $\square$ $\square$ $\square$ $\square$ $=$ $\square$ mol Cr

[Answered] Know how to handle chipped or broken glassware. Identify all actions that you should take if you have chipped or broken glassware. Notify your teacher. Have the custodian clean it up after school. Sweep it into a corner. Notify classmates. Dispose of it in the designated glass waste area.