What is the chemical symbol for Helium?

How the relative density of a substance is related to the density calculate the density of iron if its relative density is 2 and a density of water is 2gcm - 3

If a microwave oven emits 1,100 J of energy every second, how long will it take for the microwave to emit 4650 J of energy? Express your answer in seconds using the correct number of significant figures.

Zn + H2SO4 = ZnSO4 + H2

How does this splitting wedge make work easier? A) increases the applied force B) decreases the applied force C) changes the direction of the applied force D) changes the direction and amount of applied force

An element has atomic number 10 and an atomic mass of 20. How many neutrons are in the atom of this element? A. 10 B. 20 C. 30 D. 0 E. 200

1. According to the article, which country may have a greater population than China by the year 2050? A. China B. Kenya C. India D. Germany 2. What does the article list as one reason that drives couples in India to have more children? A.

How are the relationships of elements in a group different from the relationships of elements in a group

How many nitrate ions are in 387.4 grams of calcium nitrate?

Tin or silver more reactive

Chemical reactions that release energy possess reactants with lower energy than their products. True or False Heat is the most common form of energy absorbed or released in chemical reactions. True or False