Calcium's atomic number is 20. it forms ions with 18 electrons. what is the electrical charge of a calcium ion?

Select all that apply. Which of the following statements are true? Significant figures are an indicator of the certainty in measurements Significant figures communicate the level of precision in measurements Significant figures in a measurement are

Which of the following is true concerning a plot of number of neutrons vs. number of protons? A band of stability is created that is indicative of stable nuclei. The nuclei that fall outside the band undergo spontaneous radioactive decay.

The p-orbital of a methyl radical carbon, ch3·, contains how many electrons?

An Arrhenius acid has (1) only hydroxide ions in solution (2) only hydrogen ions in solution (3) hydrogen ions as the only positive ions in solution (4) hydrogen ions as the only negative ions in solution

Select the equations below that represent physical changes. Choose one or more: A. 2 H2O (l) → 2 H2 (g) + O2 (g) B. H2O (l) → H2O (s) C. CO2 (s) → CO2 (g) D. H2 (g) → 2 H (g)

What has happen to join two monosaccharide units into a disaccharide?

Choose the pair of substances that are most likely to form a homogeneous solution. a. c6h14 and c10h20 b. libr and c5h12 c. n2o4 and nh4cl d. c6h14 and h2o e. none of these pairs will form a homogeneous solution.

A glucose solution (C₆H₁₂O₆₎ has 90 g of glucose in a 500 ml flask. What is the molarity?

Atoms of cesium can lose electrons to become cations. how many electrons does a single cesium atom lose? explain your answer.

Which of the following are true about a block of ice at - 10°C as you continue to apply heat.