Given the equation representing a reaction:

2Ca (s) + O2 (g) → 2CaO (s)

During this reaction, each element changes in

1) atomic number

2) oxidation number

3) number of protons per atom 4) number of neutrons per atom

Donna is attempting to make an electromagnet to pick up old nails in and around her driveway. Which of these materials would be best to use for the core in order to make the strongest electromagnet to pick up the most nails?

The balanced equation below represents the reaction of glucose, C6H12O6, with oxygen at 298 K and 101.3 kPa. C6H12O6 (s) + 6O2 (g) → 6CO2 (g) + 6H2O (ℓ) Determine the mass of CO2 produced when 9.0 grams of glucose completely reacts with 9.

What is the ph of a 0.01 m solution of the strong acid hno3 in water?

Calculate the formula mass for the compound nitrous acid. Express your answer using four significant figures.

Identify the precipitate in this reaction: calcium nitrate reacts with sodium phosphate.

Which of the following statements is not true? Question 4 options: When atoms have similar electronegativities, electrons are shared equally When electrons are shared equally, the molecule is called a nonpolar molecule.

Write the isotope symbol for two isotopes of the same element. What makes the isotopes different? How are they similar?

According to the periodic table, which element has an atomic number of 40? a. u b. ca c. zr d. np

3. Which word best fits with the Earth's day and night cycle a. Revolution b. Rotation C Orbit d. Axis

What causes temperatures in the summer to be higher than temperatures in the winter? A. The greenhouse effect, which raises temperatures on Earth, takes place during the summer months only. B.