In a closed system, a chemical reaction takes place. The mass of the reactants in the beginning of the reaction is 25 grams. What does the mass have to be in the end of the reaction in order to follow the law of conservation of mass?

How many oxygen atoms are in Cu(KMnO₄)₃

Determine the number of hydrogen atoms in 3Ca(C₂H₃O₂)₂

The atomic number tells you what?

What is the Law of Conservation of mass?

What group number os Phosphorus in?

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

The number to the lower side of an element (H₂O) is a

Does the following equation obey the Law of Conservation of Mass?

2Fe₂O₃ + 3C --> 4Fe + 3 CO₂

How many neutrons does fluorine have?

A substance made of two or more PHYSICALLY combined substances is

Which picture represents a compound?

Which picture represents a mixture?

What period is copper in?

Which of the following are homogeneous mixtures? (Choose all that are correct!)

A mixture consists of two or more elements or compounds that are chemically combined, not physically mixed.

In a mixture, components lose their properties to form a new substance?

Two substances physically combined and that appears the same throughout is classified as

How many protons does Beryllium have?

Which set of elements in the section of the Periodic Table shown above is most similar in chemical behavior?

The position of the Sun, Earth and Moon shows which phase of the moon?

Which one of the following does NOT explain why the Moon has phases?

A full moon occurred on April 4, about what date can we expect to see another full moon?

How long does it take to complete one lunar cycle?

Which moon phase occurs about 14 days (2 weeks) after a full moon?

Tides are caused by the gravity of the

Spring tides occur during

During ___________________ tides, the moon is at a right angle to the sun.

Is this alignment for a solar or a lunar eclipse?

What is the niche of the spider in this food web?

What is the niche of the hawk in the food chain that involves the snake?

What would happen to the population of the frog in the population of the cricket were to decrease?

Which organism do the owl and the weasel compete for in the food web?

What type of symbiosis? Hummingbirds feed on nectar from flowers. The flowers are pollinated by hummingbirds as they move from flower to flower.

What type of symbiosis? Skunks often live in burrows that have been dug and abandoned by woodchucks.

Oxpeckers feed on the ticks found on a rhinoceros. The oxpeckers get a meal and the rhinoceros is helped by the removal of the ticks.

An example of an abiotic factor would be

Commensalism is similar to parasitism because in both kinds of relationship