How are elements arranged in the periodic table?

• Elements are arranged randomly without any specific order.

• Elements are arranged by increasing atomic number.

• Elements are arranged by their popularity in chemistry.

• Elements are arranged by color and shape.

What does the atomic number represent?

• The number of neutrons in an atom.

• The number of protons in an atom.

• The total mass of an atom.

• The number of electrons in an atom.

What is a chemical reaction?

• A chemical reaction is the mixing of two substances without any change.

• A chemical reaction is a process where substances (reactants) are transformed into different substances (products) through the rearrangement of atoms.

• A chemical reaction is when substances are combined to form a mixture.

• A chemical reaction is a process that only occurs in living organisms.

What is the law of conservation of mass?

• Mass is only conserved in physical reactions.

• Mass can be created in chemical reactions.

• Mass is conserved in chemical reactions.

• Mass is lost during physical changes.

What is the difference between a reactant and a product?

• Reactants are the starting materials, and products are the substances produced.

• Products are the initial materials, and reactants are the final substances.

• Reactants are formed during the reaction, and products are consumed.

• Reactants are always gases, while products are solids.

What is the symbol for gold in the periodic table?

• Au

• Ag

• Fe

• Pb

What is a molecule?

• A molecule is a single atom.

• A molecule is a group of two or more atoms bonded together.

• A molecule is a type of chemical reaction.

• A molecule is a collection of cells.

What happens during a combustion reaction?

• A fuel burns without oxygen to produce smoke and ash.

• Oxygen decomposes into hydrogen and carbon during combustion.

• A fuel reacts with oxygen to produce heat, light, carbon dioxide, and water.

• Heat is absorbed and no products are formed during combustion.

Suatu unsur netral mempunyai 2 elektron dalam kulit pertama, 8 elektron dalam kulit kedua, dan 7 elektron dalam kulit ketiga. Nomor atom unsur itu adalah:

• 2

• 7

• 8

• 9

• 17

Unsur A mempunyai 10 proton dan 12 netron, sedangkan unsur B mempunyai nomor massa 23 dan nomor atom 11. Kedua unsur tersebut termasuk ….

• isotop

• isotom

• isobar

• isoton

• isomer