A teacher put five grams of each of the four different substances into individual test tubes and then heated each test tube over a flame. The teacher asked the students to note the appearance of each
substance after heating. The results were as follows:
Reaction of Substances Table
Appearance Observations
Substance
Appearance
Before Heating While Heating After Cooling
Crackling,
black smoke
Black powder
Potassium
Purple
permanganate crystalline solid
Copper
Blue-green
carbonate
powder
Begins to
turn black
Black solid
Zinc oxide
White powder
Turns yellow
White powder
Sulfur
Yellow
crystalline solid
Yellow-brown Yellow-brown
liquid, smells liquid with large,
like rotten eggs fiber-like crystals
According to the data, which substance underwent a physical change?
A Potassium permanganate
B Copper carbonate
С Zinc oxide
D Sulfur

Your roll: experienced electron speech is adressed to: a new "freshman class" of electrons job: write a speech task: you are to pretend that you are giving a speech to a new group of electrons. be sure to mention their placement in an atom, their charge, and their role in chemical bonding (ionic and covalent) be specific!

The p sub shell can hold up to 8 electrons in an atom. true or false?

Plz me ! 1 which of earths spheres contains most of its mass? a atmosphere b hydrosphere c geosphere* d biosphere 2 erosion and weathering are examples of which types of forces? a constructive forces b destructive forces* c gravitational forces d inertia-related forces 3 which of the following statements about earths atmosphere is true? a earths atmosphere contains 78% water vapor which is essentail to life b earths atmosphere contains 21% oxygen c earths atmosphere contains carbon dioxide which all life forms require d earths atmosphere allows radiation from the sun to pass through it and warm earths surface* 4 the strenght of the force of gravity between two objects is determined by which of the following factors? select all that apply a the messes of the objects* b the distance between the objects* c the volumes of the objects d the surface area of the objects 5 earth and moon are kept in there respective orbits due to the influence of a inertia b gravity c gravity and inertia* d neither gravity or inertia if you answer all questions right i will give