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HACTEHA [7]
3 years ago
13

Which of the following is a source of chemical energy commonly used by humans? A. water flowing in a river B. a bicycle C. a san

dwich D. turning on a lightswitch
Chemistry
1 answer:
ziro4ka [17]3 years ago
7 0

Answer:

Option C sandwich is the correct option

You might be interested in
The molarity of a 2 liter aqueous solution that contains 222.2 grams of dissolved calcium chloride ( CaCl2), expressed with two
sveta [45]

Answer:

The answer to your question is 1 M

Explanation:

Data

Molarity = ?

mass of CaCl₂ = 222.2 g

Volume = 2 l

Process

1.- Calculate the molar mass of CaCl₂

CaCl₂ = 40 + (35.5 x 2) = 40 + 71 = 111 g

2.- Calculate the moles of CaCl₂

                    111g of CaCl₂ ---------------- 1 mol

              222.2 f of CaCl₂  ----------------  x

                      x = (222.2 x 1) / 111

                      x = 222.2 / 111

                      x = 2 moles

3.- Calculate the Molarity

Molarity = moles / Volume

-Substitution

Molarity = 2/2

-Result

Molarity = 1

3 0
3 years ago
If you dissolve 50.0 grams of potassium bromide in 100.0g of water what is the mass percent of the resultant solution?
tatiyna
Mass percent= grams solute/ grams of solution x 100

Mass Percent= (50/ 150)x100= 33.3%
7 0
3 years ago
Its gelatin and a fruit cup the same (its for a project)
gizmo_the_mogwai [7]

Answer:

No

Explanation:

Gelatin is a substance that makes jello, and a fruit cup is a cup full of fruit

6 0
2 years ago
Read 2 more answers
If 50% of a radioactive element remains after 4000 years, what is the half-life?
ANTONII [103]

Hey there!

A half-life means after a certain amount of time, half of that substance will be gone/changed after that time.

If 50%, or half, of the element remains after 4000 years, that means the half life must be 4000 years.

Hope this helps!

4 0
3 years ago
Pre-Lab Study Questions / 9
jok3333 [9.3K]

Answer:

See detailed answer with explanation below.

Explanation:

Valence electrons are electrons found on the outermost shell of an atom. They are the electrons in an atom that participate in chemical combination. Recall that the outermost shell of an atom is also referred to as its valence shell. Let us consider an example; if we look at the atom, sodium-11, its electronic configuration is 2,8,1. The last one electron is the valence electron of sodium which is found in its outermost or valence shell.

Positive ions are formed when electrons are lost from the valence shell of an atom. For instance, if the outermost electron in sodium is lost, we now form the sodium ion Na^+ which is a positive ion. Positive ions possess less number of electrons compared to their corresponding atoms.

Negative ions are formed when one or more electrons is added to the valence shell of an atom. A negative ion possesses more electrons than its corresponding atom. For example, chlorine(Cl) contains 17 electrons but the chloride ion (Cl^-) contains 18 electrons.

In molecular compounds, a bond is formed when two electrons are shared between the bonding atoms. Each bonding atom may contribute one of the shared electrons (ordinary covalent bond) or one of the bonding atoms may provide the both shared electrons (coordinate covalent bond). The shared pair may be located at an equidistant position to the nucleus of both atoms. Similarly, the electron may be drawn closer to the nucleus of one atom than the other (polar covalent bond) depending on the electro negativity of the two bonding atoms.

The electrons are shared in order to complete the octet of each atom by so doing, the both bonding atoms now obey the octet rule. For example, two chlorine atoms may come together to form a covalent bond in which each chlorine atom has an octet of electrons on its outermost shell.

4 0
3 years ago
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