Which of the answer choices accurately describes a trend that occurs when moving left to right across periods?

(Select all that apply.)

reactivity increases

atomic radius increases

atomic mass increases

valence electrons decrease

Write and balance the combustion equation for propane. (Propane is combusted in the presence of oxygen to produce carbon dioxide and water). 2) How many grams of oxygen are required to burn 200 grams of propane

If the experimental value for the percentage of O is 37%, The accepted value of the percentage of Oxygen is 40%, what is the error in the experiment? 6.5%08.1% 7.5% 5%

Convert 1.8 moles of potassium to atoms

When 80 g of sodium hydroxide, naoh, are dissolved in enough water to make 500 ml of solution, the molarity of the solution is?

When conducting this experiment some procedures call for heating the substance several times and recording the mass after each heating continuing until the mass values are constant. explain the purpose and how it might reduce error.

A hurricane and a typhoon are the same thing true or false?

Identify the element that chlorine forms a covalent bond with

A child pulls a sled up a snow-covered hill. The child does 405 J of work on the sled. If the child walks 15 m up the hill, how large of a force must the child exert?

A piece of glass with a mass of 32.50 g specific heat of 0.840 J/g*°C and an initial temperature of 115 °C was dropped into a calorimeter containing 57 g of water (specific heat 4.184 J/g*°C).

Which of the following is the most likely description of the product or products of a double-displacement reaction? A) one new compound B) two new compounds C) oxygen and energy D) one new compound and an element