a single atom of an element had 21 neutrons, and 20 electrons, and 20 protons which element is it? K. Zr. Ca. Sc

Given the following chemical reaction: 2 O2 + CH4 CO2 + 2 H2O What mass of CH4 is required to completely react with 100 grams of O2? 6 C 12.01 Carbon 1 H 1.01 Hydrogen 8 O 16.00 Oxygen A. 10 grams CH4 B. 20 grams CH4 C. 25 grams CH4 D. 45 grams CH4

Laura wonders why an object can ever accelerate if every force it exerts causes a reaction force. Which explanation best answers her question?

Early people observed their surroundings and relied on ...

1) Determine the number of significant figures in the measurement 6.07 m Express answer numerically as an integer. 2) Determine the number of significant figures in the measurement 0.0030 s. Express answer numerically using three significant figures.

The free energy change of the reaction A (g) ⟺ B (g) is - 32.5 kJ under nonstandard conditions. The standard free energy change of the reaction is - 42.5 kJ.

How would you be able to use the spectrum of each gas to establish its identity

Which does not add to the reliability of a scientific source of information? displaying data in a colored chart clearly identifying the sources of the data explaining how the data was collected showing that many scientists had reviewed the

Given that pH + pOH = 14, what is the pH of a solution if its pOH is 12.4?

How long does it take to anser this quesiton fist one gets brialyest

Which of the following quantities is conserved in a chemical reaction