The number of protons in an atom is defined by it's

Which statements accurately describe nonmetals? Select all that apply. Nonmetals are moldable and easily shaped. Most nonmetals are gases at room temperature. Nonmetals fracture easily under pressure. Most nonmetals are liquids at room temperature.

In this nuclear reaction equation, oxygen decays to form nitrogen. Which equation correctly describes this decay?

Which category does the ion PO43 - belong to? A. monatomic cation B. monatomic anion C. polyatomic anion D. polyatomic cation E. monatomic ion

3.75 g of an unknown gas at 59 °C and 1.00 atm is stored in a 1.35-L flask. What is the molar mass of the gas?

Is petrol hard to make

Ammonia (NH3) burns in air to form nitrogen dioxide and water. Calculate grams of nitrogen dioxide produced if 4.0 grams of ammonia are consumed

What year did mendeleev organized his periodic table in order of increasing atomic number

What is the volume of 1.9 moles of chlorine gas (Cl2) at standard temperature and pressure (STP) ? 12 L 22.4 L 43 L 81 L

This decomposition is first order with respect to phosphine, and has a half‑life of 35.0 s at 953 K. Calculate the partial pressure of hydrogen gas that is present after 70.5 s if a 2.20 L vessel containing 2.

A new element has two isotopes, one with a mass of 40.0 amu and the other with a mass of 42.0 amu. the atomic weight is 40.50 g/mol. pick the true statement a. the isotope at 42.0 amu is less abundant b. the element has 19 protons and 21 neutrons c.