When visitors enter the Children’s Science Center, they are greeted by two distinct sides of the small museum.

To the left is the Experiment Bar, where children conduct science experiments, assisted by family members, staff members and volunteers. To the right, mounted on the wall, is an enormous periodic table of elements showing the names of the museum’s major benefactors.

The Experiment Bar is one of the most popular features of the center, which offers interactive scientific activities for children and their families. The element wall honors the donors who helped open the center, marketing director Dorothy Ready said.

The element wall also provides a symbolic link between the center’s past as a museum without walls, its temporary home in a corner of Fair Oaks Mall in Fairfax County, and its future, permanent home in Loudoun County.

“There is no other place like it in this area,” Ready said, describing it as the first hands-on science museum in Northern Virginia.

The museum was bustling one weekday last month as dozens of children on field trips, participants in a week-long science camp and walk-in visitors explored the offerings.

At the Experiment Bar, children chose from a menu of lab activities, such as creating floating rainbows in test tubes. Museum staff members and volunteers answered questions and explained the science behind the experiments.

“It’s the interaction with the educator or volunteer that makes the difference, because that’s what’s memorable,” said Nene Spivy, the museum’s executive director.

“Research has shown that learning with family members is very formative,” she said. “It’s saying to the child, ‘This is really important. I value that you learn.’ ”

In a room known as “the Garage,” science campers dismantled small household appliances and used the parts for new inventions. Interactive exhibits in other rooms provided lessons on energy, gravity, magnetism, robotics, electronics and aquatic life. Throughout the space, children were encouraged to touch the materials, to be creative and to experiment.

The science center’s mall location occupies just 2,700 square feet of lab space, Spivy said. But its beginnings were even more modest. Before it secured a spot in the mall two years ago, it operated for several years as a museum without walls, bringing interactive scientific activities to schools, libraries and other public spaces.

The museum still takes its show on the road, visiting about 50 elementary schools a year, Spivy said. Last year, it served about 21,000 children off-site across Northern Virginia, in addition to 50,000 on-site at Fair Oaks, she said.

“The teachers can’t do it alone,” Spivy said. “So we see our role as supporting all the hard work that they do, and sort of greasing the wheels.”

Museum officials are in the early stages of planning for a building in eastern Loudoun, Spivy said. The developers of Kincora, a mixed-use development near Routes 7 and 28, have donated one acre for the building, which will be adjacent to 150 acres of parkland, she said, adding that a master plan is due at the end of the summer.

“We’re in the process of siting the building right now and working to get it to abut the nature trails,” Spivy said. “It will be a science center inside and out.”

Preliminary plans call for the building to grow in phases from 30,000 to 70,000 square feet, which Spivy compared to the size of supermarkets.

“It’s a massive undertaking,” she said. “But when you see the resources that are available to children all over the country, and you know how many children we have [in Northern Virginia], you just feel compelled to get it done.”

Bringing the plans to fruition will require significant gifts and public-private partnerships at the state and local levels, Spivy said. “We have to have the people that are willing to make multimillion-dollar commitments,” she said. “Everybody’s got to be at the table. It takes a region to raise a science center.”

The Children’s Science Center will have four events this month in partnership with the Loudoun County Public Library. There will be science activities for children in grades K-5 and their families at the Cascades Library, 2 to 3:30 p.m. July 11; at Sterling Library, 2 to 3:30 p.m. July 18; and at Dulles Town Center, 10 to 11:30 a.m. July 20 and 27.