Busy. Please wait.

show password
Forgot Password?

Don't have an account?  Sign up 

Username is available taken
show password


Make sure to remember your password. If you forget it there is no way for StudyStack to send you a reset link. You would need to create a new account.
We do not share your email address with others. It is only used to allow you to reset your password. For details read our Privacy Policy and Terms of Service.

Already a StudyStack user? Log In

Reset Password
Enter the associated with your account, and we'll email you a link to reset your password.
Didn't know it?
click below
Knew it?
click below
Don't know
Remaining cards (0)
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.

  Normal Size     Small Size show me how

Chemistry 1

Core Science Model Answers

Chemical equations are always balanced. Explain why. (1 mark) No atoms are lost/made (during a chemical reaction) or the atoms are rearranged (during a chemical reaction. Accept because of (the law of) conservation of mass/matter.
Why is sodium chloride a compound? (2 mark) Two different types atoms/elements/ions are bonded/joined together. Do not accept different size.
Why is titanium an element? (1 mark) All atoms are the same/it only contains one type of atom. Accept all ions are the same.
An atom of argon has 18 protons and 22 neutrons. Work out its atomic number and its mass number. (1 mark) The atomic number is 18. The atomic mass is18 + 22 = 40.
Use ideas about electron arrangements to explain why the elements in Group 0 have similar properties. (2 marks) The highest occupied energy level of each group 0 element contains 8 electrons. Because there are the same number of electrons in the highest occupied energy level of each group 0 element, the group 0 elements have similar properties.
How many elements join together to make the compound sodium chloride? (1 mark) Two – sodium and chlorine
Use ideas about atoms to explain the difference between an element and a compound. (2 marks) An element is made up of one type of atom only. A compound consists of atoms of more than one type.
Explain how sodium and chloride ions are formed when sodium chloride is made from its elements. (2 marks) When sodium chloride forms from its elements, one electron is transferred from the sodium atom to the chlorine atom. This results in a sodium ion with a single positive charge, Na+, and a chloride ion with a single negative charge, Cl-.
Explain how the atoms in a carbon monoxide molecules are held together. (1 mark) In carbon monoxide, electrons are shared between the carbon and oxygen atoms.
A molecule of sulphur trioxide consists of one atom of sulfur joined to three atoms of oxygen. Work out its formula. (1 mark) SO3
The formula of potassium manganate (VII) is KMnO4. Explain what the formula tells us about this compound. (2 marks) In potassium manganate (VII) (potassium permanganate), there are four atoms of oxygen and one atom of manganese for every one atom of potassium.
Limestone is a hard rock that is used as a building material. Limestone was used by the Egyptians to make plaster. Use the reactions of the lime cycle to explain how the plaster became even harder with age. (3 marks) - carbon dioxide / CO 2 - (carbon dioxide) reacts (with the calcium hydroxide / slaked lime / plaster) - limestone / calcium carbonate /Ca CO 3 forms - water is lost / evaporates
Created by: The Scientist



Use these flashcards to help memorize information. Look at the large card and try to recall what is on the other side. Then click the card to flip it. If you knew the answer, click the green Know box. Otherwise, click the red Don't know box.

When you've placed seven or more cards in the Don't know box, click "retry" to try those cards again.

If you've accidentally put the card in the wrong box, just click on the card to take it out of the box.

You can also use your keyboard to move the cards as follows:

If you are logged in to your account, this website will remember which cards you know and don't know so that they are in the same box the next time you log in.

When you need a break, try one of the other activities listed below the flashcards like Matching, Snowman, or Hungry Bug. Although it may feel like you're playing a game, your brain is still making more connections with the information to help you out.

To see how well you know the information, try the Quiz or Test activity.

Pass complete!

"Know" box contains:
Time elapsed:
restart all cards