Science 10 Pretest

What do you call this method in finding out the resulting compound?

• crossroad method

• crisscross method

• intersection method

• cross multiplication method

Crisscross methods are used to find out the resulting compound in a __________________.

• physical change

• physical bonding

• chemical change

• chemical bonding

When Lead (Pb) and Oxygen (O) bonded together, it will produce Lead (IV) Oxide. What is its chemical formula?

• Pb₄O₂

• Pb₂O₄

• PbO₂

• Pb₂O

How many atoms are there in 1 mole of a substance?

• 6.022 x 10^23

• it depends on its molar mass

• it depends on its atomic mass

How many grams are there in 1 mole of a substance?

• 6.022 x 10^23

• it depends on its molar mass

• it depends on its atomic mass

How many gram is 0.5 mol of Magnesium atoms? (Mg: 27 g/mol)

• 6.8 grams

• 13.5 grams

• 27.0 grams

• 54.0 grams

Lithium are used in batteries and weighs 7 g/mol. If a certain battery has 7 moles of Lithium, how many grams is the battery?

• 1 gram

• 7 grams

• 14 grams

• 49 grams

Oxygen and Hydrogen have a molar mas of 16 g/mol and 1 g/mol respectively. How many grams does 1 mole of H₂O have?

• 14 grams

• 17 grams

• 18 grams

• 33 grams

Chemical change happens when ____________________.

• chemical bonds break

• chemical bonds take place

• chemical bonds are rearranged

• all of the above

Proteins are produced from a combination of ________________.

• RNA

• DNA

• amino acids

• carboxylic acids