Cumulative Exam — Cumulative exam Answers

The equation for water is H2 +O2 → H2O. To balance the equation, which coefficient should be placed in front of H2 and H2O?

What kind of acceleration occurs when an object speeds up?

Which element is least likely to form chemical bonds?

Marco wants to investigate the chemical properties of sodium bicarbonate, or baking soda. He plans to carry out the tests below.Test 1: Mix a teaspoon of sodium bicarbonate into a cup of warm water to see if it dissolves.Test 2: Mix a teaspoon of sodium bicarbonate into a cup of vinegar to see if it fizzes.Test 3: Heat a teaspoon of sodium bicarbonate in the oven to see if its melting point is less than 400 degrees Fahrenheit.

A company that manufactures cookware has conducted numerous trials to see which metal needs the least amount of energy (measured in Joules, J) to be raised to high temperatures, and records the averages in a table. Which claim will this company most likely make?

Wanda and Marita are drinking bottles of water. Each girl sounds a different musical note by blowing across the top of her bottle.What is a good hypothesis that could lead to new experimentation?

Which describes the correct procedure when converting a number from scientific notation to standard notation?

Which statement describes an extensive property of matter?

Xander reached a final velocity of 4.5 m/s in 3.5 seconds. Finley reached a final velocity of 3.6 m/s in 4.2 seconds. Max reached a final velocity of 7.3 m/s in 1.2 seconds. They all started at the same location from rest.

Which instrument is best suited for measuring the dimensions of a shoebox?

Read the passage about the fluoridation of drinking water.Since the early 1960s, fluoride has been added to many sources of drinking water to prevent cavities in teeth. This is called fluoridation. There are some who say that this is unnecessary and increases the risk of cancer.In 1993, the Subcommittee on Health Effects of Ingested Fluoride of the National Research Council, part of the National Academy of Sciences, conducted an extensive study about the link between fluoridated drinking water and increased cancer risk. The study included data from more than 50 human disease studies and six animal studies. The Subcommittee concluded that none of the data showed a link between fluoridated drinking water and cancer. A 1999 report by the CDC supported these findings. The CDC report concluded that studies so far have produced "no credible evidence” of a link between fluoridated drinking water and an increased risk for cancer.

Which property of physical changes explains why matter is conserved in a physical change?

Scientists often work on projects for a long time and fail to see sources of error in their research. Which process allows an outside expert to look at the scientist’s project and point to sources of error?

Which statement describes the location of most metalloids on the periodic table?

Atoms of arsenic (As) are often added to silicon (Si) in a process called doping to change the conductivity of the silicon. How does the addition of arsenic change the conductivity of silicon?

When hydrogen peroxide bubbles, it is undergoing a chemical change. Which statement best describes what is happening?

What does a triple-beam balance require the user to do?

synthesispolymerizationdecompositionoxidationreplacement

The statements in the table summarize what Johannes Kepler stated in the early 1600s about the motion of planets.Kepler’s StatementsThe orbit of a planet around the sun is an ellipse.As a planet orbits the sun, a line between the planet and the sun sweeps out equal areas during equal periods of time.There is a mathematical relationship between the time it takes a planet to orbit the sun and the average distance the planet is from the sun.Over the last four hundred years, predictions based on his statements have proven true. Which best describes Kepler’s statements?

Ciara’s bike has rusted, which means that the iron in the metal changed to rust.