Calculează masa zaharului si volumul apei necesare pentru prepararea 500g de soluție de zahăr cu partea de masa 20%

What happened in 2012 and how does it illustrate the importance of understanding the sun and how it works?

As changes in energy levels of electrons increase, the frequencies of atomic line spectra they emit

Which of these statements best explains why space exploration should be encouraged? it prepares humans to live without oxygen. it dispel myths about objects in space. it prevents comets and asteroids from striking earth. it creates technology to absorb harmful radiations in space.