H pls help 1) If a neutral element has an atomic number of 18 and an atomic mass of 39.95, how many of each subatomic particle does it have?

2) Why are there many, but limited, combinations of elements to make all compounds?

3) Describe the properties of acids and bases. How are salts formed?

4) Explain the differences between mixtures and pure substances.
1) If a neutral element has an atomic number of 18 and an atomic mass of 39.95, how many of each subatomic particle does it have?

2) Why are there many, but limited, combinations of elements to make all compounds?

3) Describe the properties of acids and bases. How are salts formed?

4) Explain the differences between mixtures and pure substances.

How many moles of gas are present if p=11 atm, v=12l, t=185k?

How many atoms are there in 5.70 mol of mg

Which explanation is true about what happens to a ray of light when it strikes a mirror? a. a light ray is transmitted toward a mirror at a certain angle. the light ray is then reflected by the mirror at an equal angle but in the opposite direction of the transmitted ray. b. an incident ray strikes a mirror at an angle with a line perpendicular to the mirror. the light ray is then reflected at an angle equal to the angle of incidence but on the opposite side of the perpendicular line. c. a reflecting ray strikes a mirror at an angle with a line perpendicular to the mirror. the light ray is then refracted at an angle equal to the angle of the reflecting ray and on the same side of the perpendicular line. d. an incident ray strikes a mirror at an angle with a line parallel to the mirror. the light ray is then transmitted at an angle equal to the angle of incidence but on the opposite side of the parallel line. you so much! : -d take the time to try and answer correctly.