How many dots are shown in the electron dot diagram for calcium, in group II and period 4 with 20 protons and 20 electrons? a. four c. eight b. two d. twenty

Which of these statements is true? A. Chemical energy is a form of potential energy. B. Chemical energy is a form of nuclear energy. C. Chemical energy is associated with moving electrons. D. Chemical energy is associated with molecular motion.

What is the relationship of the number of hydronium ions (H3O+), hydroxide ions (OH-), and water (H2O) in the battery acid? What is the pH of the battery acid as indicated on the pH scale in the center of the screen?

Which of the following statements best describes chemical weathering? A. It happens only in cool environments. B. It's the type of weathering in which rocks and minerals break down into smaller pieces. C.

What elements in the building block for all other elements

The burning of a sweet potato sample generates 102.5 kJ of heat. This heat was used to raise the temperature of 300 grams of water from its initial temperature of 15.5 degrees Celsius. Considering the specific heat of water is 4.

The weighted average atomic mass of an element depends upon the a. relative abundance of protons in the element b. mass and relative abundance of each isotope of that element c. mass and relative abundance of each neutron of that element d.

What part of an atom do we change for isotopes

The Safe Drinking Water Act (SDWA) sets a limit for mercury-a toxin to the central nervous system-at 0.002 mg/L. Water suppliers must periodically test their water to ensure that mercury levels do not exceed 0.002 mg/L.

The smallest unit of an element is a blank

How many sodium atoms will create an ionic bond with sulfur?