What are the symbol, name, and atomic number of the element that has 21 protons in the nuclei of its atoms?

Which of the following statements is true regarding sodium and chlorine? A.) Sodium has greater electronegativity and a larger first ionization energyB.) Sodium has a larger first ionization energy and a larger atomic radiusC.

If two substances are mixed in a beaker and the beaker becomes hot, which of the following statements is true? The particles of the substances absorb energy from the surrounding. None of these statements are true. The mixing process is endothermic.

Which property describes an electromagnetic wave and not a mechanical wave? A. transfers energy B. travels in a vacuum C. has frequency D. requires a medium

Small, highly charged metal cations may interact with H2O to give solutions that are not neutral. Which net ionic chemical equation correctly represents the reaction of Cu (NO3) 2 with water? a. Cu2 + (aq) + H2O (l) ⇌ Cu (OH) 1 - (aq) + H+1 (aq) b.

When Mendeleev started his work on organizing the elements, about how many had been discovered? about 10 well over 100 about 60 the same as today

A change in the force of gravity on an object will affect its what

How many hydrogen atoms are in one molecule of c2h2?

Given the recipe: 2 cups flour + 1 egg + 3 oz blueberries → 4 muffins If you have 9 cups of flour, 4 eggs and plenty of blueberries, the theoretical yield of muffins is 16. A) True B) False

Where energy store at the end in a lighting candle

Which of the following does not describe a characteristic of carbon