Conservation of Mass Counting Atoms

​LET'S PRACTICE COUNTING ATOMS IN CHEMICAL FORMULAS- USE WHITEBOARDS or PAPER

​COUNTING ATOMS IN CHEMICAL EQUATION

​https://youtu.be/uJgNTeBWhDk?feature=shared

​GLOW STICK- WRITE A CLAIM OF WHAT's HAPPENING WHEN IT BREAKS?

​BAKING SODA + VINEGAR ------- explain product

Multiple Choice

Suppose you have 15g of baking soda and mix it with 15g of vinegar. When they are combined they bubble and fizz a lot. The final solution has a mass of 25g. What happened to the "lost" 5g?

• it dissappears

• it is still there just not weighted

• it is in the gas that is formed

• nothing happened

Multiple Choice

If reaction starts with 20g of reactants it should produce 

• a total of 40g of products
• a total of 10g of products
• a total of 80 g of products
• a total of 20g of products

Multiple Choice

If 20g of sugar is stirred into a beaker containing 100g of water. What would the mass of the dissolved solution be after the sugar is dissolved fully?

• 20g

• 100g

• 80g

• 120g

Multiple Choice

Which are the reactants in the following reaction?
2Mg + O₂ ---> 2MgO 

• Mg and O
• MgO
• Mg and MgO
• O and MgO

Multiple Choice

In a reaction A + B ----> C,  reactant A has 5g and product  C has 9g. How many grams does reactant B should have? 

• 4g
• 5g
• 9g
• 14g

Multiple Choice

In a reaction A + B ----> C,  reactant A has 5g and product  C has 9g. How many grams does reactant B should have? 

• 4g
• 5g
• 9g
• 14g

Multiple Choice

How many nitrogen atoms does NH₃ have?

• 1
• 2
• 3
• 4

Multiple Choice

How many oxygen atoms are in this chemical formula?

• 6 oxygen atoms
• 2 oxygen atoms
• 3 oxygen atoms
• 4 oxygen atoms

Multiple Choice

24 g of magnesium reacts with 38 g of fluorine to produce _____ g magnesium fluoride

• 62 
• 38
• 24
• 14

Multiple Choice

What is the law of conservation of mass?

• The amount of matter changes when reacted or changed.
• The mass of all reactants are changed during a physical or chemical change
• The mass of the reactants equals the mass of the products
• The mass of the products is different than the mass of the reactants.

Multiple Choice

When CaCO₃ is heated, it forms CaO and CO₂. Which of these statements best describes the mass of the products if 100 g of CaCO₃ is heated?

• The difference in the products’ masses is equal to the mass of the CaCO₃
• The sum of the products’ masses is less than the mass of the CaCO₃
• The mass of each product is equal to the mass of the CaCO₃
• The sum of the products’ masses equals the mass of the CaCO₃