An atom with 39 protons and a mass number of 89 what is the number of neutrons

explain why the hydrogen atoms in a hydrogen gas molecule form nonpolar covalent bonds but oxygen and hydrogen atoms in water molecules form polar covalent bonds

What is the specific heat capacity of silver metal if 75.00 g of the metal absorbs 56.4J of heat and the temperature rises 35.0°C?

What is the smallest part of an element that has all the properties of that element?

You are on a guided tour looking at stone statues from historical events. You observe that the newer statues are the same color, but seem to be much sharper and have more detail than the others.

Given the balanced equation representing a reaction: 2CO (g) + O2 (g) 2CO2 (g) What is the mole ratio of CO (g) to CO2 (g) in this reaction? (1) 1:1 (3) 2:1 (2) 1:2 (4) 3:2

Why does the effective nuclear charge increase across a row of the periodic table?

Iodine-131 decays to form xenon-131. the half-life of this reaction is 8.07 days. from a 200-g sample of iodine-131, how much of the sample is xenon-131 after 16.14 days?

Complete the following statement by checking all that apply Creativity allows scientists to develop multiple approaches to solving problems. adapt to changes in scientific knowledge. look at old problems in new ways.

The atomic weight of hydrogen is 1.00794. a. True b. False

Describe What kind of ions do metals form? What kind of ions do nonmetals form?