All atoms of technetium (Tc) contain:

Select one:

55 neutrons

43 protons

43 neutrons

43 electrons

What initial temperature of the copper metal which equal to the temperature of the coffee? Mass of metal = 29.8801 g T i = 18.2 degree Celsius T f = 20.1 degree Celsius Specific heat 0.384 J/g degree Celsius

Witch of these is a mixture? A. calcium B. carbon dioxide C. salt water D. potassium

Why does naphthol react with sodium hydroxide?

What is the effect of 1 mol dm-3 hydrochloric acid on a bulb? Explain why this effect happens.

What would be the density of h2 gas at 500◦c and 0.76 atm?

Which option is true about the effect of polarity on solubility? Select all that apply. Polar solutes dissolve better in water than in oil. Polar solutes have the greatest solubility in nonpolar solvents.

Which change results in a release of energy? 1. The melting of H₂O (S) 2. The boiling of water (L) 3. The evaporation of H₂0 (L) 4. The condensation of H₂0 (G)

What changes nitrogen gas in the air to nitrogen compounds that fall to the ground

Which element has an isotope mass number of 32 and is used as an ecological tracer?

Which laws can be combined to form the ideal gas law? Boyle's law and Charles's law Gay-Lussac's law and Avogadro's law Charles's law, Avogadro's law, and Boyle's law Dalton's law, Gay-Lussac's law, and Avogadro's law