How many valence electrons does calcium have?

2

5

3

8

7

1

4

6

What are the terms used to describe locations on a sand dune

If 19.2 g of O2 reacts with iron to form 63.84 g of iron oxide, how much iron in grams was used in the reaction?

How many neutrons are in the nucleus of an atom with an atomic number of 25

What structures allow T cells to locate and destroy invaders? O A. Macrophages O B. Pathogens O C. Lymph O D. Antibodies

A rechargeable battery initially stores 3.6 kJ of chemical energy. Anna puts the battery in a flashlight, where 2.1 kJ of energy are transformed into light and heat. Then, Anna puts the battery in a charger, where 6.

A particular brand of gasoline has a density of 0.737 g/mL at 25 ∘ C. How many grams of this gasoline would fill a 12.8 gal tank (1US gal=3.78L) ?

A pump contains 0.5 l of air at 203 kpa. you draw back on the piston of the pump, expanding the volume until the pressure reads 50.8 kpa. what is the new volume of air in the pump? 0.2 l 1.0 l 2.0 l 4.0 l

How can there be snow near a giraffe's home This is actually science so yeah

If a sealed syringe that contains some gas in heated in which direction will the syringe plunger move

Use the drop‑down menus to label the statements as either true of false. Dichloromethane is flammable. true false Methanol is flammable. Concentrated sulfuric acid is corrosive. 10% sodium carbonate solution must be used in the fume hood.