A helium atom has - - - protons & - - - neutrons?

A student conducts an experiment to determine the enthalpy of solution for lithium chloride dissolved in water. the student combines 5.00 grams of lithium chloride with 100.0 ml of distilled water. the initial temperature of the water is 23.

A 12.2-g sample of X reacts with a sample of Y to form 78.9g of XY. what mass of Y reacted?

Which of the following affects the rate of a chemical reaction? a. the presence of a catalyst b. the temperature c. the concentration of reactants d. all of the above

Most substances become less dense as the temperature increases. Which substance is an exception to this rule

Why is the sky blue and not red, even though blue light scatters more easily than red.

A compound is 53.31 % C, 11.18 % H, and 35.51 % O by mass. What is its empirical formula? Insert subscripts as needed.

What is the element Ar classified as in the periodic table?

Two objects, one heavy and one light, travel at one of two speeds. Which will have the most inertia?

Which statements correctly describe water boiling in a pot? Air bubbles from the atmosphere are being absorbed. The water's internal kinetic energy is increasing. The water is gaining internal potential energy. The water's temperature is increasing.

Biofuel is any fuel that is produced from living or once living matter in a short period of time, days, weeks, or even months.