Suppose the half-life of an isotope is 10 years. After how many years will half of this isotope have decayed into its daughter elements?

5 Years

10 years

20 years

2. 4 NH3 + 3 0₂ 2N2 + 6H₂O a. 20 moles of NHa are needed to produce - moles of 20. b. How many moles of Nz will be produced if 3.5 moles of Oz react?

Which acid and base neutralize to give potassium chloride salt? hf (aq) and kcl (aq) hcl (aq) and kcl (aq) hf (aq) and koh (aq) none of the above hcl (aq) and koh (aq) ?

10. Which of state of matter has no definite shape but does have a definite volume? A. Element O B. Liquid C. Gas D. Solid

Ammonia reacts with oxygen to produce nitrogen and water according to the equation below. What is the enthalpy of the reaction?

Explain why batteries and film will stay fresh longer if they are kept in a refrigerator or freezer

What would happen if leaching did not orrur?

Where does geothermal energy come from? A. sunlight B. the oceans C. the land D. inside Earth E. wind

Dimethylnitrosamine (CH3) 2N2O, is a carcinogenic formed in foods from nitrite ions used as preservatives. Calculate each of the following for this compound. Show all work for full credit. a. molar mass b. What is the % N

Does biomass energy come from petroleum?

What type of bond would occur between carbon (C) and nitrogen (N) ? A. Metallic bond B. Ionic bond C. Paired bond D. Covalent bond