Answer:
B. 4 ml
Explanation:
Volume displacement of the hammer = volume volume of water when the hammer was placed into the cylinder - volume of water only before the hammer was placed into the cylinder.
Volume volume of water when the hammer was placed into the cylinder = 69 ml
Volume of water only before the hammer was placed into the cylinder = 65 ml
Volume displacement of the hammer = 69 ml - 65 ml = 4 ml
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.
Van der waals force
Explanation:
The intermoleclular forces are attraction between molecules. Interatomic forces are attraction between atoms in a compound.
In most hydrocarbons the weak Van der waals attraction are known.
- These forces are weak attraction joining non-polar and polar molecules together.
- These forces can also be found in layers of graphite.
- They are of two types;
London dispersion forces are attraction that exists between non-polar molecules and the noble gas.
Dipole - Dipole attractions are forces of attraction existing in polar molecules.
In hydrocarbons, we have non-polar molecules and intermolecular attraction is london dispersion forces.
learn more:
Intermolecular forces brainly.com/question/10107765
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Answer:
A
Explanation:
A chemical change is when a new substance is created, which often has its own chemical properties, so A is the correct answer.
