Q: Q: What are reactions that can occur only in one direction called? Read this paragraph and choose the correct option from the provided answers: Some chemical reactions can occur in only one direction. These reactions are called irreversible reactions. The reactants can change to the products, but the products cannot change back to the reactants. These reactions are like making a cake. The ingredients of a cakesuch as eggs and flourare the reactants. They are mixed together and baked to form the cake, which is the product (see Figure below ). The cake can't be "unbaked" and "unmixed" to change it back to the raw eggs, flour, and other ingredients. So making a cake is irreversible. Choices: - permanent - instantaneous - critical - irreversible A:
A: irreversible

Q: Q: Extrusive igneous rocks are also called what? Read this paragraph and choose the correct option from the provided answers: Extrusive igneous rocks form above the surface. The lava cools quickly as it pours out onto the surface ( Figure below ). Extrusive igneous rocks cool much more rapidly than intrusive rocks. The rapid cooling time does not allow time for large crystals to form. So igneous extrusive rocks have smaller crystals than igneous intrusive rocks. Extrusive igneous rocks are also called volcanic rocks . Choices: - metamorphic - agates - magma minerals - volcanic rocks A:
A: volcanic rocks

Q: Q: What is a soft, gray, nontoxic alkaline earth metal? Read this paragraph and choose the correct option from the provided answers: For a better understanding of alkaline Earth metals, let's take a closer look at two of them: calcium (Ca) and strontium (Sr). Calcium is a soft, gray, nontoxic alkaline Earth metal. Although pure calcium doesn't exist in nature, calcium compounds are very common in Earth's crust and in sea water. Calcium is also the most abundant metal in the human body, occurring as calcium compounds such as calcium phosphate and calcium carbonate. These calcium compounds are found in bones and make them hard and strong. The skeleton of the average adult contains about a kilogram of calcium. Because calciumlike bariumabsorbs x-rays, bones show up white in x-ray images. Calcium is an important component of a healthy human diet. Good food sources of calcium are pictured in Figure below . Choices: - pewter - magnesium - potassium - calcium A:
A: calcium

Q: Q: What is the study of structure, properties, and interactions of matter? Read this paragraph and choose the correct option from the provided answers: Chemistry is the study of the structure, properties, and interactions of matter. Important concepts in chemistry include physical changes, such as water freezing, and chemical reactions, such as fireworks exploding. Chemistry concepts can answer all the questions on the left page of the notebook in Figure below . Do you know the answers?. Choices: - petrology - biology - geology - chemistry A:
A: chemistry