How to tell if a reaction is endothermic or exothermic by looking at it?

Which of the following terms describes the reactivity of boron tribromide, BBr_3? a. Lewis base and not a Bronsted-Lowry base b. Bronsted-Lowry base and Lewis base c. Lewis acid and not a Bronsted-Lowry acid d. Bronsted-Lowry acid and Lewis acid

The solar wind carries mass away from the Sun at a rate of about 1.5 million tons per second (1 ton = 1000 kg). At this rate, how many years would it take for all of the Sun's mass to escape?

Which of these periods contain elements with electrons in s, p, d, and forbitals? A periods 1-3 B. periods 1-4 C. periods 3-5 D. periods 6-7

The ingredient label for a fruit drink reads: water, sugar, orange juice, high fructose corn syrup, vitamin C, sodium benzoate (preservative), Red 40, Blue 1.

A circuit contains two light bulbs connected in parallel. What would happen to the brightness of each light bulb if two more light bulbs were added in parallel to the first ones?

What is more dangerous, current or voltage? Why?

What is the significance of the symbol of an element?

Consider the half reactions below for a chemical reaction. 2 Equations: First: upper M g right arrow upper M g superscript 2 plus (a q) plus 2 e superscript minus.

If you put some sodium chloride (table salt) into a glass of water, what will happen?

Why don't the inert gases easily react with other elements?