What does isoelectronic mean

Describe the characteristics that identify a sample of matter as a substance.

The average atomic mass of iron is 55.845 amu. this average mass represents?

On Earth an object weighs 50 N. On Planet X, the object weighs 500 N. What conclusion can be drawn from these observations? A. Planet X has less mass than Earth. B. Earth has a greater diameter than Planet X. C.

An iodine atom has seven valence electrons. Do you think it will lose seven electrons or gain one electron to obtain an octet in its outermost electron shell? Explain

Water molecules are listed from A to B to C in A) greatest to least motion. B) least to greatest motion. C) least to greatest density. D) greatest to least rotation.

Which of the following happens during a chemical change? Check all of the boxes that apply. One atom or more changes into atoms of another element. New substances with different properties are formed. Solids, liquids, or gases may form.

What material was added to powdered rock during tuttle and bowen's experiments?

Which of the following statements is true? Selected Answer: D. At least two of the above statements (A-C) are true. Answers: A. Ions are formed by adding or removing protons or electrons. B. Scientists believe that solids are mostly open space. C.

Does anybody know which element from the periodic table that has 19 electrons and 24 neutrons, for atomic charge.

Given the following reaction 2Al + 3Cl2 - -> 2AlCl3 How many grams of AlCl3 aluminum chloride will be produced from 125 g of Al and 125 g of Cl2?