The question is incomplete; the complete question is;
In the early 1900s many scientists thought that an atom consisted of a positive substance with negative charges scattered throughout the substance. Then Ernest Rutherford completed an experiment that changed the concept of an atom. His discovery led to the understanding that an atom consists mostly of empty with space with-
Protons orbiting a dense nucleus made of electrons and neutrons
Electrons orbiting a dense nucleus made of protons and neutrons
Neutrons and protons orbiting a cloud of electrons
Electrons and protons orbiting a cloud of neutrons
Answer:
Electrons orbiting a dense nucleus made of protons and neutrons
Explanation:
Rutherford established the nuclear theory of the atom by his famous experiment. In his experiment, alpha particles were used to bombard a thin gold foil and the movement of the particles was observed on a moveable zinc sulphide screen.
It was discovered from the experiment that the atom was mostly made up of empty space. The electrons orbit a dense nucleus comprising of protons and neutrons.
Answer:
The balance equation is
→ 
Explanation:
first, we have to make sure that the atoms are balanced
→ 
→ 
then we proceed to balance charges of each half-reaction
→ 
→

Now we multiply the half-reactions to match the number of electrons in each one
(
→
)x2
(
→
)x3
and now we do the sum of the half-reactions
2
→ 2
→ 3

→ 
note: the only atom that needed to be balanced was I
Heat_1: Get the ice to 0 degrees
Convert 7 kg to grams
7 kg [1000 grams / 1 kg] = 7000 grams
Heat needed to get the the ice from - 9 to 0
deltat = 0 - -9 = 9 degrees
m = 7000 grams
c = 2.1 joules/gram
Heat_1 = m*c*deltat
Heat_1 = 7000 * 2.1 * 9
Heat_1 = 132,300 joules
Heat_2: Melt the ice.
There is no temperature change. The formula is 333 j/gram
Formula: H = mass * constant
H = 7000 g * 333 J / gram
H = 2331000 joules
Heat_3: Total amount of Joules needed.
2331000 + 132300 = 2 463 300 joules
Convert to Megajoules
2 463 300 joules * 1 megajoule / 1000000 = 2.63 megajoules.
Answer:
neon is the Noble gas but I have not studied this much
Explanation:
Lead(II) phosphate is an ionic compound with chemical formula Pb3(PO4)2. Lead(II) phosphate is a long-lived electronically neutral reagent chemical.[1] Despite limited tests on humans, it has been identified as a carcinogen based on tests on animals conducted by the EPA.[2] Lead(II) phosphate appears as hexagonal, colorless crystals or as a white powder. Lead(II) phosphate is insoluble in water and alcohol but soluble in Nitric acid (HNO3) and has fixed alkali hydroxides. When lead(II) phosphate is heated for decomposition it emits very toxic fumes containing Lead (Pb) and POx.[3]