an element has atomic number 10 and an atomic number mass of 20. How mamy neutrons are in the atom of this element?

What volume does 0.056 moles of H2 gas occupy @ stp?

A student wants to prepare 250.0 mL of 0.10 M NaCl solution. Which procedure is most appropriate? (formula Molar Mass of NaCl = 58.4 g/mol) A) Add 5.84 g of NaCl to 250. mL of H2O B) Add 1.46 g of NaCl to 250. mL of H2O C) Dissolve 5.

Phosphoric acid is added to many popular beverages to give them a tart flavor. the formula of phosphoric acid is 1. h2po4. 2. h3po4. 3. hpo4. 4. h4po

Which of the following is true about the compound MgBr2? Question 2 options: A magnesium atom gained 2 electrons, while two bromine atoms each lost 1 electron. A magnesium atom lost 2 electrons, while a bromine atom gained 2 electrons.

Which has greater precision, the 10 ml graduated cylinder or the 50 ml graduated cylinder?

Which statement is true about inorganic compounds? A. They are not made of atoms. B. They contain carbon. C. They are not made from living things. D. They are all elements.

Which domain do you find the most interesting why

Complete the matching exercise below by choosing the correct description of each bond type in aqueous solution. 1. covalent bond 2. hydrogen bond 3. electrons shared by atoms a. electrons shared by atoms b.

One mole of calcium ions has the same number of representative particles as which of the following? one mole of calcium nuclei one mole of calcium atoms 6.02 x 1023 calcium ions All of these are correct.

How is chemical symbol and chemical formula difference?