How many neutrons does element x have if its atomic number is 42 and its mass number is 160? neutrons?

A container of gas has a pressure of 2.76 atm at constant temperature. If the volume of the gas in the container expands from 10.0 L to 15.0 L what is the new pressure?

Find out no. of moles present is 72 gm of water?

What are the three types of matter?

The substance water always has a mass ratio of 11% H to 89% O. If 5.00g of a substance containing H and O was decomposed into. 290g H and 4.71g of O, is the substance water?

Which statement best defines specific heat? A. The amount of heat required to increase the temperature of 1 mol of a substance by 1 °C. B. The amount of heat required to increase the temperature of 1 L of a substance by 1 °C. C.

Which terms are used to identify pure substances? (1) an element and a mixture (2) an element and a compound (3) a solution and a mixture (4) a solution and a compound

Which of the following polyatomic ions will form an ionic compound with two sodium ions? CO32- HCO31- NO21- NO31-

What is hybridisation

2. Seorang ibu perlu menyediakan satu hidangan kari daging dengan cepat untuk anaknya yang lapar. Langkah manakah yang berikut dapat membantu dia mencapai tujuan ini? (CL01, C2) A. Menggunakan periuk yang lebih besar B. Menambah banyak serbuk kari C.

Which of the following statements is not true? Question 4 options: When atoms have similar electronegativities, electrons are shared equally When electrons are shared equally, the molecule is called a nonpolar molecule.