Calculate number of hydrogen atom present in 40g of urea,(NH2)2CO ​

What semimetal can form four single covalent bonds.

In a reaction equation, where are the products located? a.) above the arrow b.) to the right of the arrow c.) to the left of the arrow d.) below the arrow

Which theory was contradicted by experiments with the photoelectric effect? light spreads out after it passes through a small opening. as soon as light strikes metal, electrons will be ejected. visible light, regardless of color, will cause the ejection of electrons when striking metal. the kinetic energy of ejected electrons depends on the frequency of light that strikes the metal.