If 50% of radioactive element remains after 4000 years what what is the half life

What criteria are used to classify matter?

EX: The periodic table is arranged in order of increasing from left to right, and elements in the same column have the same number of EV. ri.

What type of glass is formed when calcium carbonate is heated with silicon dioxide?

Which of the following devices is based on the property of thermal expansion? a. balance b. calorimeter c. convection oven d. thermometer

Use the term selectively permeable in a sentence

What's the difference between Mixture and Solution?

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Nitrogen and hydrogen react to form ammonia as described by the chemical equation below: N2 + 2 H2 → 2 NH3 If you start with 2 moles of N2, how many moles of NH3 can you make? Fill in the t-chart below to answer the question.

In which substance do the molecules have the strongest attractions to one another?

Which of the following correctly describes a property of an atom? it has more protons than neutrons it has a negative or positive charge it has an equal number of protons and electrons it has an equal number of neutrons and electrons