Answer:
<em>What is atmospheric pressure? -------> Atmospheric pressure is a force in an area pushed against a surface by the weight of the atmosphere of Earth, a layer of air.</em>
<em>Why does the atmosphere exert pressure? -------> Because gas particles in the air—like particles of all fluids—are constantly moving and bumping into things, so they exert pressure. </em>
<em>What is the value of atmospheric pressure at sea level, in newtons per square centimeter? -------> Atmospheric pressure at sea level is about 10 N/cm2 or 100 kPa or about 10 m of water or about 760 mm of mercury, but varies with the weather, and of course altitude.</em>
<em>I hope this helps and have a great day!</em>
Explanation:
Answer: pure substances.
Explanation:
The given substances are:
All what surrounds us, which has mass and occupies spaces, is matter. There are two kind of matter: pure substances and mixtures.
Pure substances have a uniform and constant composition. On the other hand, mixtures are combinations of two or more pure substances in any arbitratry ratio.
Pure substances may be elements or compounds. The elements are the substances conmposed by one only kind of atom. In the list of substances given, Li and O₂ are elements: all the atoms in Li are lithium, and all the atoms in O₂ are oxygen atoms.
Compounds are the chemical combination of two or more different kind of atoms. In the given list H₂O₂ and NaCl are compounds. As you see, H₂O₂ contains atoms of hydrogen and oxygen, chemically bonded, in a fixed ratio (2 atoms of hydrogen by 2 atoms of oxygen). And NaCl has atoms of Na (sodium) and Cl (chlorine), chemicaly bonded, in a fixed ratio (1:1).
There are only 118 known elements and you can find them in any modern periodic table. Therer are virtually infinitely many compounds since many different combinations of the elements can be attained.
Elements and compounds have in common that they are classified as pure substances.
Answer:
D
Explanation:
i took the test and got it right :)
Answer: 5.4
Explanation:
P2 = P1V1/V2
P2 = (.60atm x 27L) / 3.0L = 5.4atm
C. Sulfur and oxygen (non metals) forms a covalent bond while the magnesium (a metal) will react with both non metals to form an ionic bond
