Chemical Reactions

Harrison is making cake. He prepares some batter and places it into the oven. Harrison realizes a gas, carbon dioxide, is coming out of the batter as it bakes.

Harrison está haciendo pastel. Prepara un batido y lo mete en el horno. Harrison se da cuenta de que sale gas, dióxido de carbono, de la masa mientras se hornea.

Which options are true about carbon dioxide?

¿Qué opciones son ciertas sobre el dióxido de carbono?

• It is a new gas that forms during baking.

• It is made of atoms that did not exist before.

• It is the dough changing states from solid to gas.

• It is formed from the atoms of the batter

Tags

NGSS.MS-LS1-7

NGSS.MS-PS1-2

The element sodium (Na) is a soft solid that will react explosively with water. The element chlorine (Cl) is a toxic gas. When these two elements combine, they produce a stable, crystalline solid known commonly as table salt (NaCl).

How would you explain this?

El elemento sodio (Na) es un sólido blando que reacciona explosivamente con el agua. El elemento cloro (Cl) es un gas tóxico. Cuando estos dos elementos se combinan, producen un sólido cristalino estable conocido comúnmente como sal de mesa (NaCl). ¿Cómo explicarías esto?

• When substances combine to form new substances, the properties of the reactants are preserved.

• The properties of each of the two original elements are combined to give salt its properties.

• Sodium and chlorine become different elements during the reaction.

• When substances combine to form new substances, the properties of the resulting substances will be different.

Tags

NGSS.MS-PS1-2

Consider burning a hot cheeto. This is a chemical reaction. The hot cheeto, flame, and oxygen in the air enter a chemical reaction and produce ash and some other things.

Considere quemar un cheeto caliente. Ésta es una reacción química. El cheeto caliente, la llama y el oxígeno del aire entran en una reacción química y producen cenizas y algunas otras cosas.

Which statement would be true?

• Ash is a different substance than the hot cheeto.

• The atoms of wood and oxygen disappear during the burning.

• Ash has similar properties to oxygen.

• The atoms of the ash did not exist before.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Complete the sentence.

During a chemical reaction, atoms ________.

Completa la oración. Durante una reacción química, los átomos ________.

• can appear

• can disappear

• get rearranged

• stop moving and vibrating

Tags

NGSS.MS-PS1-5

What always happens in a chemical reaction?

¿Qué sucede siempre en una reacción química?

• Some atoms of existing substances disappear.

• Some substances change phase.

• New atoms appear and form new substances.

• New substances form from atoms of existing substances.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Identify the product(s) in the following chemical reaction:

Chromium oxide + Carbon → Chromium + Carbon monoxide

• Chromium and carbon.

• Chromium and carbon monoxide.

• Chromium and carbon dioxide.

• Chromium oxide and carbon.

Tags

NGSS.MS-PS1-2

How many iron (Ag) atoms are reactants in this equation?

4Ag + 3O2 → 2Ag2O

• 4

• 2

• 3

• 0

Tags

NGSS.MS-PS1-5

Why are numbers placed before the elements and molecules in a chemical equation?

¿Por qué se colocan los números antes de los elementos y las moléculas en una ecuación química?

• To represent if an element or molecule is a liquid, gas, or solid.

• To balance the equation so that it has the same number of atoms of each element on each side.

• To make sure there's always more reactants than products.

• To show whether a substance is an element or molecule.

Tags

NGSS.MS-PS1-5

In chemical reactions, a product is _________.

En reacciones químicas, un producto es _________.

• any substance that is made of the greatest number of atoms

• any substance that is made from the least number of atoms

• any substance that is to the left of the arrow

• any substance to the right of the arrow

Tags

NGSS.MS-PS1-5

What is the role of the arrow sign in a chemical reaction?

¿Cuál es el papel del signo de flecha en una reacción química?

• Making sure atom counts on each side are the same.

• Separating products and reactants.

• Showing which substances were in the container first and which substances were added later.

• Showing which substances are solids and which are liquids or gases.

Tags

NGSS.MS-PS1-5