Question

i do: what kind of matter is baking soda (nahco₃)? explain your thinking
we do: you add water, salt and sand to a bottle and shake it up. what type of matter is present in the bottle? a) pure - element b) pure - compound c) mixture - heterogeneous d) mixture - homogeneous explain your selection.

Explanation:

For the first question, baking soda ($NaHCO_3$) is made up of multiple elements (sodium - Na, hydrogen - H, carbon - C, oxygen - O) chemically combined in a fixed ratio, so it is a compound. For the second question, water, salt and sand are different substances not chemically combined. Sand will not dissolve in water and salt - water solution uniformly, so it is a heterogeneous mixture.

Answer:

I do: Baking soda ($NaHCO_3$) is a compound because it is composed of multiple elements chemically bonded in a fixed proportion.
We Do: c) Mixture - Heterogeneous. Explanation: Water, salt and sand are different substances not chemically combined. Sand does not dissolve uniformly in the water - salt system, creating a non - uniform mixture.