Answer:
The smallest particle of a chemical element can be defined as an atom.
Explanation:
The number of protons in one atom of an element determines the atom's identity, and the number of electrons determines its electrical charge.
a single electron or one of two or more electrons in the outer shell of an atom that is responsible for the chemical properties of the atom is known as valence electrons.
An atom's reactivity is its tendency to lose or gain electrons. ... This is because they have one outer electron and losing it gives them the stability of a outer electron shell as the next level... The reactivities of elements can be predicted by periodic trends.
Answer:
A. It is possible not all of the water was evaporated from the sand, causing the recovered mass to be higher
D. While drying the NaCl, the liquid boiled and some splattered out of the evaporating dish, causing the recovered mass to be higher.
Explanation:
Sand absorbs water and stores it. The sunlight causes the water to evaporate but sand can hold some of the water inside it. This results in increase in mass of the sand. The mass of sand before and after the water evaporation can be different.
Answer:
a) 
b) 
c) 
Carbon: 
Explanation:
<u>Nitrate</u>
First of all, is important to know that:

a) 10 ppm of nitrate (
) is equal to 
b) The molecular weight of nitrate is 


c) Nitrate has 14 mg of N per 62 mg of NO3

<u>Carbon</u>
Carbonate has 12 mg of C per 60 mg of 
Bicarbonate has 12 mg of C per 61 mg of 


Answer:
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Calculate the density by dividing the mass by the volume.
Using the equation density = mass/volume, you can determine the density of water. Plug in the values of mass and volume you determined and solve.
Explanation: