Which of these elements is a metal?

Hafnium

Radon

Silicon

Sulfur

Selenium

If 76 grams of Nal are dissolved in enough water to make 225.0 mL of solution, what is the molarity of the solution? (2.25 mol/L)

An empty 3.00 l bottle weighs 1.70 kg. filled with a certain wine, it weighs 4.72 kg. the wine contains 11.5% ethyl alcohol by mass. how many grams of ethyl alcohol are there in 250.0 ml of this wine?

For the reaction represented by the equation ch4 + 2o2 ® co2 + 2h2o, how many moles of carbon dioxide are produced from the combustion of 100. g of methane?

Which element has properties most similar to Bromine? A) F B) Kr C) S D) Se

A reaction was conducted between barium nitrate and sodium phosphate. 3 Ba (NO3) 2 + 2 Na3PO4 → 6 NaNO3 + Ba3 (PO4) 2 What is the percent yield if 0.3 mol Ba (NO3) 2 and 0.25 mol Na3PO4 react to produce 0.095 mol Ba3 (PO4) 2?

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?

A car is driven through streets treated with salt and then parked in a warm garage. a) How will the rate of rusting compare with a car that has not been driven in the streets treated with salt but left parked outside?