Atom
Elements and Compounds
Chemical Reactions
Water
Difficult Definitions
100

The negative charged particles of an atom are called ...

electrons

100

What element has chemical symbol of H?

Hydrogen

100

Group of two or more atoms make up a ...

molecule

100

What is the chemical abbreviation of water?

H20

100

A connection between two atoms is called a 

chemical bond

200

What are three types of particles atom is made of?

protons, neutrons and electrons

200

All chemical elements are organized in a …

Periodic Table of Elements

200

Which process is expressed by this equation?

6CO2 + 6H2O  → C6H12O6 + 6O2

photosynthesis

200

True or False - water is inorganic compound?

True

200

What is matter?

Anything that has mass and takes up space

300

Which subatomic particles are in the nucleus of an atom?

protons and neutrons

300

What is NaCl?

salt or Sodium Chloride
300

Where can you find the reactants in a chemical equation? e.g. 2Na + Cl2 --> 2NaCl

On theleft side 

2Na + Cl2


300

Water and salt mix evenly and therefore create a 

solution

300

Macromolecules or organic compounds consist of 5 basic elements. The elements are: 

Hydrogen, Oxygen, Carbon, Nitrogen, and Phosphorus

400

What is the difference between number of electrons and number of protons in a neutrally charged atom?

There is no difference.

electrons = protons

400

What is a definition of a compound?

a substance containing different elements e.g. H20

400

What does the coefficient in front of a substance in a chemical equation tells us? e.g. 6CO2

The number of molecules

e.g. 6 carbon dioxides

400

Why do we call water a universal solvent?

Water dissolves more substances than any other chemical.

400

A substance's mass per unit of volume is called

density

500

What do you call an atom that is either positively or negatively charged?

ion

500

What does the atomic number of an element in the periodic table mean? E.g. Helium has number 2

Number of protons in the nucleus

500

Why are the chemical equations always balanced?

Atoms are neither created nor destroyed so all the reactants on  left side must equal to products on right side. (Law of Conservation of Matter)



500

How does water change with temperature and why is it good for living organisms?

Water reacts very slowly to temperature and therefore keeps homeostasis = stable internal environment in living organisms

500

The amount of a substance in a defined volume (grams per liter) is called

concentration